It would be REALLY nice to be able to rename files or copy them using the script just like suggested 5 years ago in this thread:
http://www.adventuregamestudio.co.uk/yabb/index.php?topic=22163.0 (http://www.adventuregamestudio.co.uk/yabb/index.php?topic=22163.0)
Doing batch files to run your own app before running AGS isn't too elegant :)
Yes, I would actually find both File.Rename and File.CopyTo useful functions.