Mailist to discuss all issues regarding the Digitech GSP-2101 Guitar FX Processor

I am looking for the easiest way to control the master volume with the
expression pedal on my control one. I am using only the digital FX
(analog bypassed)of the 2101 in my setup (via the stereo FX Returns
jacks). I want to assign the expression pedal to control only the
volume of every preset that I use. (basically act as a standard volume
pedal).  Anyone know how to do this with the analog section bypassed?