...
extern "C"{
   bool WINAPI ConnectFB(char* szDSN, char* szUId, char* szPwd);
}
....

...
bool WINAPI ConnectFB(char* szDSN, char* szUId, char* szPwd){
...
}
...

EXPORTS
ConnectFB 	@ 1 

...
typedef bool (CALLBACK* lpDllEntryPoint)(char*,char*,char*);
...
HMODULE dllmodule = NULL;
dllmodule = LoadLibrary("*.dll");
if(dllmodule==NULL) AfxMessageBox("*.dll not loaded");
else{
   FARPROC lpDllEntryPoint = GetProcAddress(dllmodule, _T("ConnectFB"));
   if (lpDllEntryPoint != NULL){...}
   else AfxMessageBox("ConnectFB not loaded");
}
...