Separation of tracks (staves) for a piano piece

Hello everyone,

I've transcribed a short piano piece using MS, with the intention of transferring it on my Yamaha keyboard as a MIDI and playing the tracks (left hand and right hand) separately, in Learning Mode. Since I created the file as two separate staves (using the Piano template), I expected the contents of the G clef stave to be seen by the keyboard as the "right hand" track, and the F clef stave to be seen as the "left hand track". Instead, the notes on both staves are merged into a single track, and so I can't play LH and RH separately.

Of course, the software can't know which note will be played by which hand, but it can safely assume that whatever the user puts on the G clef stave should go to the right hand, and what he puts on the F clef should go to the left hand.

I then transcribed the same piece using a different notation software (Guitar Pro 6), again being careful to put each note where it belonged (either to the LH or to the RH); the MIDI produced had the two staves (tracks) nicely separated when played back on the keyboard - which is what I also expected of the MIDI produced with MS.

Can anyone help? Many thanks in advance!