You can get a pretty reasonable approximation of a DOS box under XP if you try.  I know of a few utilities that give your XP dos boxes emulated old-school Sound Blaster 16 support and the like.  There's lots of stuff like that on SourceForge.  (can't remember the URL - just google search for sourceforge and you'll go right there.)
If you're looking for a front end, try MameWah for a simple one or 3dArcade for that "wow" feeling.  (and look on the software forum.)
-EDIT-  and if you get your DOS progs running nicely under XP using anything on SourceForge, PM me cuz I've been toying with that as a sort of side project...  trying to get my old Ultima Underworld games to work nicely under XP dos boxes.   
