|More to the point, it isn't included in xp.|
This place seems to be offering a download, scroll down to "F" (I can't vouch for it's integrity).
Copy "forfiles.exe" to:
and it should work.
Where %systemroot% is a system variable normally pointing to "c:\windows".
Forgot to mention that although it mentions Win2000 it should work just fine on xp. Win2000 is about as close as you can get to xp...