I just reread the original question. XP is based on the same kernel as 2000, which is based on NT. Unlike Win95/98/98SE/ME, it is not a GUI running on top of a DOS system. That doesn't mean that you can't run DOS programs, though.
There used to be a DOS replacement environment for NT environments called 4NT. It was made by the same people as 4DOS. Let me see if I can find a link.
I don't know if the software will run under it, but this provides a DOS environment running in a window under an NT based system. The manufacturer's web site is:
http://www.jpsoft.com/
They have a 21 day evaluation period on the latest version...it's shareware.
I've used their programs for years, on all kinds of machines, and have never had any trouble with them. I even chose 4DOS as a command interpreter, back when command.com was the only game in town!
-- Chuck Knight