Elektron Musical Instruments

I have kind of a silly question.  Anyone know how to automate decay on 
the monomachine? I'm trying to send a control change from Cubase.  
Instead of messages 1-127, the monomachine's implimentation chart 
lists  3a, 3b, and 3c for decay, release and volume respectively.  
Control message 3 is mute on/ off.  Not sure what this means.  Any 
help would be appreciated.  Thanks.

Brian