MOTM

Hi all,
 I'm getting ready to do some recording (needed by tonight) and thougt I'd 
ask the list this question... Is there anyway to use my Yamaha FC-7 
(sweepable & passive) footpedal as a modulation signal attentuator?

 I'd like to use it to introduce some kind of tonal change in a solo I'm 
about to record, but can only do this if it's an easy (quick) thing to setup. 
I'd imagine it would have to be connected in series with whatever I want to 
control? 

 Thanks for any help,
  Andrew