Code in the attached file, along with documentation. Note that I use the ego view for buttons (as I said, I am not a graphic artist). The first the buttons from the left are number buttons, and add the numbers 1, 2 and 3 to the keypad text. The next button cancels, the one after that is backspace, and the last one OK. It would be great if someone would help me make better graphics for the demo code. Instructions are in the documentation. You will also need to add the word 'keypad' to your vocabulary.
Lars