Roy, I'm a little confused by your question.
On a Midi Track, you can specify the midi input as any midi device you want, so you could record midi and then assign the envelop to anything you want.
This is a video that shows how to use a controller to actually control any parameter in the DAW (more or less) using ACT.
http://www.youtube.com/watch?v=Ja1RvsICh0Y