XP - 2K Question - Please help!!

We have both Windows XP and Windows 2000 desktops in our environment. I
would like to run certain things during the login script that only run on
the Windows XP machines. Is there a way to do this. For example, is there
a particular file that only exists on XP and not on 2K that I could use the
IF EXIST variable in the login script? Or perhaps is there a way that I
could use something like IF VER=?????? GOTO XP and run the certain commands
from the XP label?

I would really appreciate any help with this.