What is the Windows Message send when '+' is pressed on the Number pad? also the '-' on the number pad Windows Message?
BTW if you know the message fo MFC that would be great if not great again
WM_KEYDOWN or WM_KEYUP, your window has to have the focus, I believe mfc is OnKeyUp and OnKeyDown
If you need to always thieve the key then you can use hooks
Also check out PreTranslateMessage().