Hi Athena the Femme Fatale,
Yep, it's a simple copy and paste job. Your Window's installation will simply give it a different file name with "Copy of" as the prefix and the game files simply will not recognise it as the origional file due to it's new name! If you desire to use the back-up copy all you have to do is delete the non-backup file, give the back-up it's name and the game will recognise it again. Hope this helps you, good luck with your modding, cheers!