Batch save old files in new documents with same name but with one addition.

Hi, sorry for the confusing headline..

I'm trying to write a script and I'm really having a struggle.

Problem:

I want to batch save files as new documents, with the old name but with the addition "-fixed".

The key is that I need to make a fresh file, I can't just duplicate them. I've tried using actions but

I'm stuck when it comes to renaming the new document with the same name as the old one but with the addition.

This one is pretty close:

Re: How to copy filename and paste as text in Photoshop

But I can't seem to get the filename into the copy memory.

Any kind of help would so great.

Thanks!