.bat file help lz ! :)

On XP and such, you can get the desktop path by grabbing the user's profile directory (the environment variable "HOMEPATH" or "USERPOFILE"- I'd recommend the latter since it seems like one that would exist on older systems) and then appending '\Desktop' to it.

So, basically, it would be:
copy *.* %HOMEPATH%\Desktop\

I think.