CINEMA LENS ANAMORPHIC ADAPTER NEED TO KNOW

[rchristianf11@gmail.com]

I have a 5Diii with the Xeen Cinema lenses 24, 50, and 85, mounted on rails with a matte box. I know there are matte box filters to mimic the anamorphic look, but is there an anamorphic adapter for the larger cinema lenses? OR is it possible to have the adapter behind the lens mounted to a mirrorless camera?