Key Mapping

Does anyone know who to program the basic keyboard-Keytronic to allow the + or the enter key to perform the tab function without buying a program to do this. The Keytronic keyboards we use do not have the key mapping functionality. I was wondering if there was a registry edit I could do. The other option was to put the keyboard icon on the desktop and allow the teachers to toggle back and forth between the qwerty and the dvorak keyboard so when teachers enter grades they can use one hand instead of two.