class A : public CObject
{
public: 
A();
virtual ~A();
int ACCUAPI FunctionX();
int ACCUAPI FunctionY(TCHAR FAR * ParamA );
};

#include "head.h"

typedef int (*MYPROC)();
.
.
.
void CTest2Dlg::OnOK() 
{

HINSTANCE hinstLib;
// Get a handle to the DLL module.
// in the debugging this handler gets a value (i.e. not null)
hinstLib = LoadLibrary(TEXT("Mydll.dll")); 
if (hinstLib != NULL) 
{
// in the debugging “ProcAdd” returns null
ProcAdd = (MYPROC) GetProcAddress(hinstLib, TEXT("FunctionX "));
// If the function address is valid, call the function.
if (NULL != ProcAdd) 
{
// do something
}
}
}