The simplest way to use C code from VB

For instance say I want to do a faster directory tree search like this code offers instead of using API calls or adding a Folder or File control to the forms and reading from it take this C code and show the easy way to call this from VB and return the filenames\paths for credit:
            
    //***************************************************************
    // Name: How to search a directory tree For files
    // Description:The following code sample illustrates how to search from a given directory downward through the entire directory tree. The sample output from this example is directed to the system debug screen.
    For this example, the first class member (below) is called by a menu item. After the search is finished, a message box pops up. http://www.concentric.net/~cgalbrai/dirsrh.shtml
    // By: Found On the World Wide Web
    //
    //
    // Inputs:None
    //
    // Returns:None
    //
    //Assumes:None
    //
    //Side Effects:None
    //
    //Code provided by Planet Source Code(tm) (http://www.Planet-Source-Code.com) 'as is', without warranties as to performance, fitness, merchantability,and any other warranty (whether expressed or implied).
    //***************************************************************
   
    void CTestView::OnSearch()
          {
          
          // szFilename is declared in the header as array of char
          // look For MyFile.txt (or whatever)
          
                strcpy(szFilename,"MyFile.txt");
          
          // go to root directory (or to whichever directory that you wish)
          
                _chdir("C:\\");
          
          // search For the filename
          
                SearchDirectory();
          
          // announce when done
          
                MessageBox("Done Searching");      
          }
    SearchDirectory() is called initially from OnSearch(). SearchDirectory() is Then called recursively (from itself) until the End of the directory tree is reached and all branches are searched.
          void CTestView::SearchDirectory()
          {
                struct _finddata_t filestruct;
                long hnd;
                char buffer[_MAX_PATH];
          
          // set _findfirst to find everthing
          
                hnd = _findfirst("*",&filestruct);
          
          // If handle fails, drive is empty...
          
                if((hnd == -1)) return;
          
          // Get first entity on drive - check If it's a directory
          
                if(::GetFileAttributes(filestruct.name) & FILE_ATTRIBUTE_DIRECTORY
                      && !(::GetFileAttributes(filestruct.name) & FILE_ATTRIBUTE_HIDDEN)) {
                
          // If so, change to that directory and recursively call SearchDirectory
                
                      if(*filestruct.name != '.') {
                      
                            _chdir(filestruct.name);
                      
                            SearchDirectory();
          // go back up one directory level
                      
                            _chdir("..");
                      }
                }      
                else {
          // If it's not a directory and it matches what you want...
                      if(!stricmp(filestruct.name,szFilename)) {
          // output the filename With path to debugger
                            _getcwd(buffer,_MAX_PATH);
                            strcat(buffer,"\\");
                            strcat(buffer,filestruct.name);
                            strcat(buffer,"\r\n");
                            OutputDebugString(buffer);
                      }            
                }
          
                while(!(_findnext(hnd,&filestruct))) {
                
                      if(::GetFileAttributes(filestruct.name) & FILE_ATTRIBUTE_DIRECTORY
                            && !(::GetFileAttributes(filestruct.name) & FILE_ATTRIBUTE_HIDDEN)) {
                      
                            if(*filestruct.name != '.') {
                                  _chdir(filestruct.name);
                            
                                  SearchDirectory();
                            
                                  _chdir("..");
                            }
                      }
                      else {
                      
                            if(!stricmp(filestruct.name,szFilename)) {
                                  _getcwd(buffer,_MAX_PATH);
                                  strcat(buffer,"\\");
                                  strcat(buffer,filestruct.name);
                                  strcat(buffer,"\r\n");
                                  OutputDebugString(buffer);
                            }
                      }
                }
          
                _findclose(hnd);      
          }