I'm in the middle of re-tiling a bathroom floor that will necessitate a change in the height of the closet flange. What's there now is a 3" copper and there's absolutely no play in the pipe, nor practical (easy) way to change it.

I've played with a couple of plastic fittings and I can get the required height but I need a way to transition to copper. I looked at a couple of rubber couplings but didn't see anything likely to work.

Are there specific PVC to copper couplings?