The great circle distance ORD-NCE is 4541 so a round trip is over the 9000 mile limit. In order to stay under 9000, you will need to have an open jaw somewhere.
Some possibilities are: ORD-LHR-NCE//MAD-ORD or YYZ-LHR-NCE-MAD-ORD or ORD-LHR-NCE-MAD-IAD. I think you get the picture. Good luck.