[sdiy] idea for a controller, or does this already exist?

[Samppa Tolvanen]

Hi,

At least to demo your idea If you're using a computer and midi
keyboard with your setup, you could check out Bome's Midi Translator
http://www.bome.com/midi/translator/

This piece of software can be used to translate between different midi
events or even event types. So you could use it to "catch" some note
on event and translate its velocity information to midi CC message.

Bye, Samppa