How do I create a different file name format than the ones provided?

What file contains the file name templates? My naming convention for files is "Artist-Album-Number-Track Title" which is not offered. I found the file and modified it about a year ago and it has been working nicely until yesterday when I use the program preferences to change it to "Track Title" for one CD. I planned to go back into the file and change it again but now I can't find it. I'm running 8.4 now. Thanks