Defining surface impedance for superconducting resonators in CST Microwave Studio

I'm trying to simulate a superconducting microwave resonator using CST Microwave Studio, and need to take account of the kinetic inductance to accurately model the resonant frequency. I've tried defining an additional reactance through a material with a tabulated surface impedance, up to several orders of magnitude higher than the geometric inductance, but have seen no effect on the resonant mode.

Has anyone had some experience in simulating such materials in CST?