The movie lens was designed to project the world onto a movie frame (reductions of 1000x); but an enlarging lens is designed for magnifications around 10x-40x, and that's a big difference! So you can use the movie lens -- straight -- but you'll have to accept a lesser quality result, especially for large magnifications. Still, for smaller prints or the occasional enlargement, it might meet your needs. The biggest obstacle will be adapting the movie lens to an enlarger board. The movie lens will have either a C-mount or D-mount screw thread on it. Some camera shops, such as Calumet (in Chicago) have enlarger flanges that take that size. There are also enlarger converters from C to 39mm. Another approach is to make your own lens board. Cut a piece of balsam wood to the correct size for the lens board. Then cut a hole in the middle just smaller than the tread size. The balsam wood is so soft, you can thread the lens right into it. Another approach is to tape the lens to a stiff cardboard lens board. You can also have a lens board drilled to the size you need at a machine shop. Just get an undrilled board -- most manufacturers make these -- and look in the Yellow Pages for a shop near you. The C-mount is 1 inch in diameter (32 threads per inch), while the D-mount is 5/8 inch in diameter (32 threads per inch).
One problem with short focal length lenses is that many enlargers were not made to accept a lens shorter than 35mm. Using or making a recessed board might solve this problem, but with a movie lens you might not want to use the lens in the standard position.
There will be less optical compromise if the lens is used in the reversed position (depending on lens construction, of course). The very best "enlarging" lens for the Minox, I found, is a KernSwitar VarioSpecMikMak with macrofocusing. It was intended as a 16mm cine lens, specially mounted and corrected for microscope and bellows use. Horribly expensive 40 years ago - but I found one used on a dead Bolex 16 camera for $30 -- and its a jewel. The only obstacle is figuring out a way to get it attached to your enlarger in the reversed position. If you simply reverse the lens board, the lens ends up INSIDE the enlarger -- not too easy to use, but do-able The process is a lot easier if the lens has a front filter thread -- and many movie lenses do. You might be able to find step up rings, if it is a standard size, or you can get creative with a little glue -- after all you won't be using the lens for anything else!
Finally, for best results, try using a simple movie lens. Specifically, this means a single focal length, slow lens. A fast lens is nice on the camera, but in the darkroom it is a hindrance, and usually means less quality. A 4.5 or 3.5 aperture is all that you need. Similarly, pass on the zoom lens. They may be tempting, but usually give less sharp results than a simple lens. They are less likely to fully cover the image, as well.
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