Hmm, this is probably the one you used on your Win2k machine all those years ago.
m3u Playlist Copier - Programm m3u listis olevate lugude kopeerimiseks
(don't worry the page is in English)
Basically, search the internet for "copy mp3s from m3u to another folder". I remember opening my m3u playlist a while ago, it's a readable text file with each song's entry being a path to the song file, should be trivial to write a utility to parse this to do what you want. I don't move my song files around much so haven't had the occasion to try this out.