Xpantastic!

>
> But will it work in Pedal Input 1 & 2 in my Xpander? I'm confused. How
> can a MIDI controller be a 1/4" jack, and how the heck can it be in stereo?

You would have to assign Pedal 1/2 to a CC#.
But I believe pedal 1/2 are intended to be used as on/off switches,
not sources that can vary a signal, as in a volume pedal.
I may be wrong.

If your pedal has a pot in it, try assigning it to CC7 in the xpander
and assign that to a VCA, see if your volume changes.