Mirror effect

Hey all! I have a question about an effect I'm thinking of. I have 10 moving fixtures in a row. I want them all to start at a center point (5 stage right facing in, 5 stage left facing in) >><<. Then fan out and dim from the outside inward <<>>, mirroring stage left and right. Then come back to the center, rinse and repeat. I would like to build this as an effect and not a cue/step. I hope this makes sense. Thank you!