Casio CZ/ VZ/ FZ - Pro Series

I really want a knob/wheel to program the CZ.

I gave up on reverse-engeneering approaches but thought of a simpler
and more universal solution: a little PIC reads the rotation of an
encoder and outputs the corresponding +/- key presses at high speed to
the keyboard interface, using a pair of opto-couplers.
Has anyone done this, is it available anywhere?

Joaquim