Question about Working with Audio Channels in Sony Vegas 11

Try the following:

First, duplicate the audio track two times (both channels contained in it) and then mute it (this is your back up in case you change your mind).

Second, right-click on the track wave form of the first duplicate audio track, then select Channel, then Swap (left and right are swapped).  Slide the Pan to the Left.

Next, right-click on the track wave form of the second duplicate audio track, then slide the Pan to the Right.

Hope this works for you.