Does anyone know how I can create a lesson file for a Yamaha keyboard.

Well my keyboard is a DGX 500 and It has these lessons where you practice 3 ways with each hand separately, while the other hand is being played by the keyboard.

This is what the description of the keyboard states :
Yamaha Education Suite™ Learning to play songs and chords
The DGX500 comes with 100 built-in songs with Songbook. But if you've never played before, where do you start? Well, if learning to play music is important to you, the Yamaha Education Suite II™, a wonderful set of music training functions, makes learning music incredibly easy. Seven types of lessons are available as well as a convenient chord dictionary.

* Three keyboard lessons for each hand
Timing mode: You can play the melody or chord by pressing any key using the correct timing.
Waiting mode: Playback pauses until you find and play the correct chord or melody note.
Minus One mode: Mute the left-hand, right-hand, or both parts of a song and play along nonstop.
* Lesson Grading— monitors your progress as you practice each lesson.


I know there must be some way to do this, because I realized some midi files I created were able to work on this function from my floppy disc, but I only one hand had both hands programed on it...

This was purely accidental when I did it so I don't know what I did differently for those file then the others.