OK, this isn't wuite what you're looking for but if you have a quick search through the MOD forums, you should be able to dig out the Quote Hack Mod. What this does is when a user click son Reply with Quote in a post instead of this:
quote:Dummy text dummy text dummy text
you will get this:
quote:Originally posted by someone: Dummy text dummy text dummy text
To do it the way you want would probably require a major tweak in inc_functions.asp, I'll look into it over the weekend, if I get the chance.