Well, things are going nicely here; I settled on an underscore to denote uppercase, and a through-slash (| or /) for digits. The only problem I had defining stuff was i, which should be |; that stroke was defined as a character looking like an i, but with no dot. Since I couldn't find that character to disable it, I used \ instead.

Things work rather well now; better than in Vista on my tx2000, where I'm writing this...