This works for old film and might work for new. I used this technique to make copy negs of severely damaged important BW negs for a special collections department when I was in college. Imagine putting together a floating emulsion puzzle some days.

You will need distilled water, foto-flo or something similar, a tray, squeegee, what you are transferring to, a temporary base bigger than the original and something like fixed out film or over head transparency film, micro spatula, scalpel or exacto, and lots of patience.

Score or cut a couple millimeters off the edges off the film. Use a new Exacto or scalpel. Put the neg in very warm-hot distilled water and a couple drops of foto-flo

If it is going to work you will see the emulsion begin to come off as it expands in the warm water. This can take a really long time. I would keep my tray on a heating pad and do something else while I waited. Some popped right up others took a LONG time

If the edges start to come off calm down take a deep breath and get comfortable. Get the micro spatula and start working it VERY slowly between the emulsion and the base. Be patient, work very slow. It will not just come off.

Eventually you will have the base separated from the emulsion. Take out the base, and slide in the temp base. If you try to take the emulsion out it will be destroyed. Slowly position the emulsion onto the new base and gently raise it out of the tray straight up. If you tilt, the emulsion will most likely slide off.

Place the temp base and emulsion onto piece of glass place the permanent base on top of the emulsion. It has to be dry. Squeegee the two together. Most of the time you should be able to peel the temp base off with no issue. The dry permanent base will hold the emulsion. I destroyed a lot of meaningless negs figuring out how to do this and I did not need to do it on anything color, or younger than the 1960s. I did try and was able to do it on a negative from the eighties but that was one negative.

Hope this helps.