ExcelBanter - changing function keys in windows xp

OK, I'm getting a little desperate here. My real problem is with windows xp,
but i can't seem to get any of the links to workso i can ask this same
question in their discussion forum...i get "error on page" at the bottom of
my screen and the page doesn't load or change at all. Here's my problem: my
zero key broke on my laptop. I've found a workaround in word and excel by
programing the f11 key to be the zero and shift+f11 to be the right
parenthesis in word, and by doing an auto correct feature in excel. But my
problem is that in any other program I want to use, i have to copy the zero
from another program and paste it where ever I need it. How can i program a
function key or create a shortcut key in windows xp, so that each time i hit
it, no matter the program, it'll always type a zero. Or, how can i get my
question posted on one of the windows xp discussion groups.