Hi rlaine,
You will need to modify your above patch slightly. You should use:
input > ampmod
sidechain > envelope in
envelope out > ampmod mod
ampmod > output
Then set the settings on the ampmod and envelope such that you get the desired effect.
You can easily test if the sidechain input is working by connecting sidechain directly to the output and seeing if the audio from the sidechain buss now comes out the output.
Dan
