How to find the ascii values for SHIFT+ KEYS

I want to find the acii value for the shift+keys.

 I have edit controls in my project and i want to allow the entry of
  numbers alone and "." for decimal point,so this my coding i have
  done in the pretranslatemessage().



BOOL CTrans::PreTranslateMessage(MSG* pMsg)
{
     // TODO: Add your specialized code here and/or call the base class
         
          char q[10];
           ::GetClassName(::GetFocus(),q,10);

     
      if(strcmp(q,"Edit")==0)
      {

          CWnd* ww = GetFocus();

          switch(pMsg->message)
           {
 
             case WM_KEYDOWN:
                    {
               
                 CString str;
              ww->GetWindowText(str);
        if(pMsg->wParam==190  && str.Find(".",0) ==-1)
           return  CDialog::PreTranslateMessage(pMsg);
          if(pMsg->wParam ==9 ||pMsg->wParam ==27||pMsg-
           >wParam >= 36 && pMsg->wParam <= 39 || pMsg-
           >wParam==8) return CDialog::PreTranslateMessage
           (pMsg);
                 
     if(!isdigit(pMsg->wParam))
     if(!(pMsg->wParam==46|| pMsg->wParam==8))
      return true;
     )
                 
          }
     }
     
     return CDialog::PreTranslateMessage(pMsg);
}



for the key 1 to 0 and for the . key when i use the shift keys !,@,#,$,%,^,&,*,(,),> are entered in the edit control I don't want the shift+key operation to work.

   help me regarding this.