I have a old model (CosmosEx first sold model) B with two USB ports. It doesn't have bluetooth installed internally. And sorry I misspoke. All instructions online are for Retropie installations. There are these videos that explain how to download specific drivers that are required to download.https://m.youtube.com/watch?v=Q4K3h4CIJwA
This video in particular shows how to work with a 8bitdo controller, but its basically the same. But I don't think that CE runs off of Retropie so I don't think it would have this install. I will try sitting down with it today, but I don't think it will work.