I actually just tried it myself, so it must work for you too... ;-)
So:
- you move all your music to H (more or less keeping the same folder structures - the more you change that, the more work it will be)
- create a Library for all your music on H
- copy your playlists to the MB Library on H (or have you made them there? that would be even easier)
- (you can check now: if you open a playlist, C and F files will have kind of warning 'file is missing' - I guess this is what you've noticed yourself already, so you must have done what I mention before - sorry for the redundancy)
- relink the music file paths
- solved... :-D (or I have misunderstood your problem)
b.