How To Automatically Pan Between Channels?

Hello there!

I'm fairly new to Audition and this might be a dumb question but..

I am making 8D Audio and would like to automatically pan between the left and right channels (don't really care for the back channels because it can't be heard through headphones). I found a video on Youtube that shows how to "write" or manually change the angle so that sound comes out of a specific part of the surround sound channels. (Link: How to Create 5.1 Surround Sound Audio in Adobe Audition - YouTube )

I can't sit here and manually change the angle between -90 and 90 perfectly so I was wondering if there is a way to write an expression (similar to After Effects) to make it pan from -90 to 90 in 5 seconds and keep repeating this throughout the entire song?

Any and all help is very much appreciated!

Cheers!