I am controlling the pitch of an Electroharmonix V256 Vocoder pedal with the awesome Arturia Keystep. The control is working fine. However, I want to adjust the fine tune of the Vocoder's internal synth to match my other instruments. (I play in A=432hz). The Vocoder can change fine tuning through midi on CC 15. After reading both manuals, I haven't been able to figure out how to get the keystep to adjust that CC. Any tips would be greatly appreciated!