Assuming the file is the same as your other posts:
"C:\Anime\music\gunsmith_cats_-_hateshinai_toiki.mp3 Hateshinai Toiki" Unknown

Code:
alias mp4.play {
  var %a = $read($mircdirmp3\mp3list.txt,%mp3.songnum)
  echo -a $mid(%a,2,$calc($pos(%a,.mp3,1) +2))
}