Excel .xlsm file with a VBA macro that will sweep through a list of folders and rename all the tracks to a standard format. It renames "Trackname 001.mp3" to "001-Trackname.mp3" and "Album - 01 - Trackname.mp3" to "01-Album-Trackname.mp3". It skips files without track numbers so it won't affect your playlist files.
If required, I can add function to recurse through all subfolders, just contact me for more info. Likewise if you need this file in Excel 2003 format.