Teunis,

I do this ALL the time with Piano, but I do it a different way, in Real Band.

I regenerate the track in Real Band and click the "also generate real chart" option and it gives me a midi piano track of the performance, which I then use with software in exactly the way you have described.

Also, many of the piano tracks have a Hi-Q instruments equivalent and have the same number, so you can do it that way do.

Might save a little time.