Is it possible to define a custom index - for the JSON song array?

[liamcrean]

Via the CMS I'm using - it'd be great to be able to use a track entry a the index, rather than the 0-x numbering a default. So in the array it'd look something like:

"name": "Song Name 99",
"artist": "Artist Name",
"album": "Album Name",
"url": "/song/url.mp3",
"custom_song_index": "99"

"name": "Song Name 199",
"artist": "Artist Name",
"album": "Album Name",
"url": "/song/url.mp3",
"custom_song_index": "199"

Which could then overwrite the numbering output in in playlists, something like:

"playlists": {
    "playlist_title": {
      	custom_song_index: [99, 199]
    	} // playlist