Set your program to load and run OnBoot and off you go!.Craft your control program using the mapping.Map out the pins either by examining the contact matrix, or by.(It goes without saying, that soldering will be required.) Disassemble it and take the controller and usb plug section, then wire-up your 'controller' to the contact connections intended for the keyboard matrix.Buy a cheap usb keyboard, the ones that are like $5 to $20 or so.

However, for any others with a similar question, I propose the following solution: Given the time between the OP and now, this may be moot.