Accepting input from the Numeric Keypad

Question

I learn by doing and have been writing a simple RPN Calculator program to help. So far it works fairly well as long as I click on the buttons using a mouse. I want to be able to accept inout from the Numeric Keypad as well. I have accessed the help function and have tried to implement the "Public enum Keys" function but have not gotten beyond the definition stage. Can anyone point me in the direction of a tutorial, help file, or other resource that would help me implement keyboard input for a running program? Basically, I want to be able to either click on the "1" button or press the number "1" on the keyboard and have a "1" entered into the appropriate textbox. Any assistance would be greatly appreciated.