Neutral Race Shipset

Is there an easy way to make the Neutral Race Shipset, I believe listed as "Default" in the Empires folder available for use when creating a *.emp file in a custom game?

If I understand the file structure correctly I could say copy the Terran folder into a new folder and then copy the files from Default into the new folder and painstakingly rename each of the associated files "new_folder_fighter.jpg" etc. essentially creating a new empire but there must be a better way. Either that or does someone know of a good free utility for batch/wild card renaming files in mass?