Retract when paused

[Katwitch]

I have a multi color print project that I'm doing with my M2 Dual V4 hot end. I'm using Simplify 3D and have M0 set in the Process Change Script for each layer that requires a color change. I would like to add a retraction to the same process change script, so that filament does not continue to ooze while I make the change. What commands can I use to accomplish this?