Doepfer

I have a few modules I'm making at the moment (very slow and lazily 
though :-D): Attenuator module, different multiples, extension 
module, distortion, front to rear connections, manual gate, speaker.
Anyway, I just thought about making my Stylophone into a module 
(probably still powered from its battery), use it to control the 
VCO's or send CV's out. I have to somehow find the sound source of 
the Stylophone and redirect the cv's from the keyboard to a jack 
socket.
Anybody tried this or have any tips for me?