I use Windows Commander, a shareware program that can rename files that way. I does a lot of other things too. I use it instead of Windows Explorer for copy, rename, move, zipping etc etc etc.
I have used WIndows Commander to change a group of files at once from the KN6000, it does make it a lot quicker and easier.
Here is the address for that program
http://www.ghisler.com/ Marilyn