It remains lost....
The code you can see is what remains of the Protracker playroutine for that chip tune you can find. Unfortunately, its nothing but empty DOS tracks in front of the code, therefore the meaningful code to actually run the secret part has been erased.
There is a part of the playroutine, then there is some graphics (most likely the font(s)) and then the chip tune.
This is just from examining the disk as is. Unless the code is elsewhere on the disk (and thats a big if!), then its lost I'm afraid.