Not long ago, I bought a little USB 10-key number keypad to use with Live, thinking that having numbers to fire off the numbered scenes in Live would make sense. Unfortunately, as many have discovered, you can't key map anything in Live other than the alphabet keys. This seems like a pretty big oversight since the scenes are already numbered and other keys like + and - make sense for increasing and decreasing values.
So, in order to get my nice little 10-key device to work with Live, I had to download a key remapping program from this guy and it seems to have done the trick!
I have been able to remap the 1-9 keys on my 10-key device to QWERTYUIO and they trigger events in Live just as they would if I were using the alpha keys.
As a caveat, I should mention that this application works by changing the windows registry and that makes these changes global. So if you turn all of your regular number keys into letters, don't be surprised if you can't type "1234" anymore. But with the additional 10-key pad, this works like a charm. I have yet to try it out in a live situation, but I'll let you know how that works.
Just thought I would share since I was struggling with a way to get around this myself for a while.