How to have files have 2 names, my file name and client file name?

I need to name files for a corporate client in a very specific way for them, however I'd rather also keep my file name structure. I could output the files and rename them, but then when they come back to me and ask for retouching etc on a particular file, I wouldn't have that name in my archive (I'm delivering several thousand files).

Is there a way to have 2 files names associated with the files, or embed the original file name in the files metadata somewhere. Please keep in mind there are several thousand files, so need this to be automatic.

Thanks!