Just found this very useful app. Its freeware.
what it allows you to do is rename large amounts of file names, this is especially useful for things like renaming resouces so they can be used in your paint app. like changing .grd gradients in photoshop so they become .PspGradients
obviously just renaming a file doesn't always work, but in some cases it allows use in another app, which is great when pysodelic just upped 6000 gradients for photoshop
to use simply install and run, locate the folder you want to convert then put in the file extension you want to change, and what you want to change it to and hit rename. easy