I am trying to research an adapter that will make it possible for me to mount an XL lens to my Ef mount EOS camera. Any help will be appreciated!
I don't believe anyone has or can make this, for the same reason you can not easily mount a mirco 4/3 lens to a DSLR. If flange distance and sensors are smaller the lens are smaller and closer to the sensor of such systems/mounts. If you try to convert them to a larger mount like EF then you will have problems with vignetting from the sensor seeing the inside of the barrel, as well as you would not be able to focus at infinity if you move the flange distance further out. Wiring can also be an issue which is why cheap adapter don't bother and then you have a manual lens on your camera. It is far easier for companies to prepuce adapters to place larger lenses on smaller formats.
The Fotodiox Pro Lens Mount Adapter Canon EOS/EFs to Canon XL Mount allows you to use available lenses that feature a Canon EF or EFs mount to fit on a camera body with a Canon XL mount. ... The adapter mounts to the lens and is removable, so you can use one adapter on many different lenses.
Just to clarify he wants to go from XL to EOS, mounting down to a smaller mount is fine but a smaller lens on a larger format will not work.