I had the bathroom floor built up with marble tile about 1 inch above the current closet flange (PVC materials); consequently, I have to raise the flange. The flange attaches directly to a closet elbow so I don't believe that I can cut that elbow from the inside and extend it with a coupling, new pipe, and new flange.

I realize that there are extensions but then the closet bolts would be too short.

Any suggestions to raise the flange to about 1/4 inch above the finish floor?