There is a Pan and Volume automation envelope function.
The line that runs down the center of a track (in multitrack mode) is for pan, and the line at the top is for volume.
You might have the envelopes hidden. To un-hide them, push the little buttons at the top that look like these (Cool Edit Pro, Audition might be slightly different). The one that says L/R should be pushed in, in order to use the pan envelope.