Is there anything better than %random%

I am writing a program that copies one program infinitely to another location. Here is a part:

@echo off :place Xcopy C:\Whatever C:\SomethingElse\%random%* Goto :place

Thats it. The asterisk is there so that xcopy assumes it is a file name, not a directory. Unfortunately, %random% stops somewhere around 32k-37k, and it isn't really random. For my purposes, i need this to really go forever, or at least into the billions. Are there any ways to do this? Thanks.