Application API/asm hook

Okey, My little question goes like this. How do i inject a text on the asm mark "0x0050105C"
In this case 0x0050105C contains a version number. So what i want is a dll code that replaces that value with 0x0290.
I got the c++ source for this, but i thought sharing a delphi solution would be cool too.

The code for that goes like:

#include "Extend.h"

//global vars
const char * UserInfoPacketFormat = "cdddddSdddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddffffddddSdddddcccddhbcdcddddddddhhdhddddcdddddd";

#ifdef __DEBUG__
      //global fstream
      ofstream file("4extend.log", ios::trunc);
#endif

//DLLMain
DllExport BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpReserved)
{
      //msg box captions and messages
      const char * MsgBoxCaption = "Extender",
             * ErrMsgOpenProcess = "OpenProcess() failed.",
             * ErrMsgReadProcessMemory = "ReadProcessMemory() failed.",
             * ErrMsgWriteProcessMemory = "WriteProcessMemory() failed.",
             * ErrMsgVirtualProtect = "VirtualProtect() failed.";

      //Server Protocol Revision
      const WORD NewServerProtocolRevision = 0x0290; //656
      //Server Window Name (Default: Release-1(fastest), [ServerStatus])
      const WCHAR * NewServerWindowName = L"Extender 2.1 [me@me.com]";

      //our DLL state switch
      switch( fdwReason )
      {
            case DLL_PROCESS_ATTACH:
            {
                  //temp var for ReadProcessMemory()
                  SIZE_T temp = 0;
                  //LPVOID buffer[8];
                  //temp var for VirtualProtect
                  DWORD oldProtect = NULL;
                  
                  //Get the current (applicationserv) Process ID
                  DWORD dwProcessID = GetCurrentProcessId();
                  HANDLE dwHandle = OpenProcess(PROCESS_ALL_ACCESS, false, dwProcessID);
                  
                  //Checks if our Current Process (applicationserv) Handle is valid
                  if (!dwHandle)
                  {
                        MessageBoxA(NULL, ErrMsgOpenProcess, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                        file << "OpenProcess failed.  Error Code: " << GetLastError() << "\r\n";
                  }
                  else
                  {
                        #ifdef __DEBUG__
                              file << "Got Process Handle " << dwHandle << ".\r\n";
                        #endif
                  }


                  //New Server Protocol Revision
                  if( !WriteProcessMemory(dwHandle, (LPVOID)(0x0050105C+1), &NewServerProtocolRevision, sizeof(NewServerProtocolRevision), &temp) )
                  {
                        MessageBoxA(NULL, ErrMsgWriteProcessMemory, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                        file << "WriteProcessMemory on applicationserv.0050105D failed.  Error Code: " << GetLastError() << "\r\n";
                  }
                  else
                  {
                        #ifdef __DEBUG__
                              file << "Wrote applicationserv.0050105D with new Server Protocol Revision [" << NewServerProtocolRevision << "].\r\n";
                        #endif
                  }

                  //New Server Window Name
                  if( !WriteProcessMemory(dwHandle, (LPVOID)(0x004907A9+1), &NewServerWindowName, sizeof(NewServerWindowName), &temp) )
                  {
                        MessageBoxA(NULL, ErrMsgWriteProcessMemory, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                        file << "WriteProcessMemory on applicationserv.004907AA failed.  Error Code: " << GetLastError() << "\r\n";
                  }
                  else
                  {
                        #ifdef __DEBUG__
                              file << "Wrote applicationserv.004907AA with new Server Window Name.\r\n";
                        #endif
                  }
                  
                  
                  
                  //if( !ReadProcessMemory(dwHandle, (PVOID)&RecvPacketAddr, buffer, sizeof(DWORD), &temp) )
                  //      MessageBoxA(NULL, ErrMsgReadProcessMemory, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                  //else
                  //{
                  //      
                  //}

                  //VirtualProtect for Receive Packet Function Hook
                  /*if( !VirtualProtect((LPVOID)(0x19930520), 32, PAGE_EXECUTE_READWRITE, &oldProtect) )
                  {
                        MessageBoxA(NULL, ErrMsgVirtualProtect, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                        file << "VirtualProtect on applicationserv.19930520 failed.  Old Protect: " 
                              << hex << oldProtect << " Error Code: " << GetLastError() << "\r\n";
                  }
                  else
                  {
                        #ifdef __DEBUG__
                              file << "Set protection on applicationserv.19930520 from " << hex << oldProtect << " to " << PAGE_EXECUTE_READWRITE << ".\r\n";
                        #endif
                  }*/

                  //Receive Packet Function Hook
                  if( !WriteProcessMemory(dwHandle, (LPVOID)(0x0050F8F4+1), &HookReceivePacket, sizeof(&HookReceivePacket), &temp) )
                  {
                        MessageBoxA(NULL, ErrMsgWriteProcessMemory, MsgBoxCaption, MB_OK || MB_ICONSTOP);
                        file << "WriteProcessMemory on applicationserv.0050F8F5 failed.  Error Code: " << GetLastError() << "\r\n";
                  }
                  else
                  {
                        #ifdef __DEBUG__
                              file << "Wrote applicationserv.0050F8F5 with ReceivePacket Hook (" << temp
                                     << " bytes).  New call address: " << hex << HookReceivePacket << ".\r\n";
                        #endif
                  }

                  //UserInfo Packet Function Hook
                  /*

                  */

                  break;
            }
            case DLL_THREAD_ATTACH:
                  break;      
            case DLL_THREAD_DETACH:
                  break;
            case DLL_PROCESS_DETACH:
                  break;  
      }  
      return TRUE;
}

void HookReceivePacket()
{
      #ifdef __DEBUG__
            file << "Entered HookReceivePacket: now calling applicationserv.005509E2.\r\n";
      #endif
      __asm
      {
            mov            eax, 0x005509E2
            //mov            eax,500FF0h            //call our applicationserv function
            call      eax
      }
      #ifdef __DEBUG__
            file << ">>>>>> HookReceivePacket: now calling ReceivePacket.\r\n";
      #endif
      __asm
      {
            push    edi      //var something
        push    eax      //var something else
            call    ReceivePacket      //call our own packet handler
      }
      #ifdef __DEBUG__
            file << ">>>>>> HookReceivePacket: ReceivePacket has returned.  Now finishing and calling applicationserv.0050F8FC.\r\n";
      #endif
      __asm
      {
            mov     eax, [esp]
            cmp     byte ptr [eax], 0A8h
            jbe     short ESP_OK
            mov     byte ptr [eax], 0A8h
            mov     word ptr [eax-2], 1
      ESP_OK:
            add     esp, 0Ch
            push    0x0050F8FC
            //retn
      }
      #ifdef __DEBUG__
            file << "Exited HookReceivePacket. \r\n";
      #endif
}

void ReceivePacket(BYTE * header, BYTE * packet)
{
      #ifdef __DEBUG__
            file << "Entered ReceivePacket.  Header: " << &header << " Packet: " << &packet << "\r\n";
      #endif
}

void HookCharInfoPacket()
{
      
}

void HookUserInfoPacket()
{
      
}


Would appricate all help on this matter