Excel has a built in Calculator that has a keypad that can be controled by the mouse.

It will do what you want, just don't press the + - / etc. keys.

I also suggested this at your cross post. http://www.mrexcel.com/forum/showthread.php?t=485259

In the future would you please remember to post links to cross-posts. The link in my signature explains how to do this and why it is requested.