Ok - I'm staring at my Waves C1/sc plugin screen and I can't figure it out either now, a mate has the manual so I'll have to go get it off him. The s/c in the C1 looks like it can only be a filtered copy of the input. This sucks ! I think it's maybe my fault for suggesting you used it in the first place, foolish assumption that the sidechain supported it.

And I just found an article in SOS with a picture of the things in Cubase from last month and guess what ... cubase's built in ones dont' support sidechaining at all.

This on the other hand if you can find it might work:

http://www.db-audioware.com/dbd-guide.html

Stupid software, never realised it was missing in so many applications ...