Right click on the audio track , then Insert/remove envelope ,surround pan keyframes.
You should now have a keyframe line beneath your audio track.
If you then right clcik on the surround panner & select "surround panner" that will open the panner up.
Click on the keyfrane timeline where you would want to place the keyframe , then drag the point on the panner to where you want to place the sound & it will automatically create a keyframe on the keyframe timeline.

This is is Acid Pro 4.0 - I'm assuming you should see it similar in VV4 if that is what you are using but I haven't tried it there.

Perhaps not very eloquently explained , but I'm on the verge of running out the door so I'll check later to see if that helped. If not I'll try again.