Hello,
From your post I am not certain what problems you are having. If you could answer a few clarifying questions then perhaps I can get you on your way.
1. Are you trying to model the empirical dielectric data you have for bulk Cu2O? If so have you looked at the dispersive materials, specifically Lorentz-Drude material? There is a fit data button which will allow you to calculate the coefficients required to model your material.
2. For your second problem, are you asking how to create a hollow sphere? If so the trick is to actually create 2 spheres, one with your outer radius and set it to Cu2O and one with the inner radius and set it to air.
Scott