Padding is easy yes, but most people would set the padding to two characters. In the CDex case, the track number comes as 4 or 5 chars (1/11 etc), so this wouldn't pad correctly. Ignoring the CDex case and no problem, but I can't do that. Otherwise you pad to 5 chars and have 00001 for non CDex tracks (which looks kinda dumb) and 01/11 for CDex tracks. I could start getting smart and looking for the / etc but I think the ID3v2 track field is a string of variable length whereas the ID3v1.1 track field is 2 chars only.

I don't have my development environment here, so I'm not sure if playlist position is easily available. I assume it's there somewhere though. I'll see what can be done.