It might be possible to do this using Fred Mellink's KN SD-Explorer Tool. It isn't very expensive and would save you literally hours of work. I suggest you get in touch with Fred, he'll soon tell you if it can be used. Sorry I do not use midi/audio files at all, so cannot tell you anymore than that.

Another person who could possibly help you is Bill Norrie. I think he has Fred's tool as and also uses midi/audio files.

Good luck