CST spatial dependent dielectric constant

Hi there,
I want to investigate non homogenous dielectrics in CST. I have not found any method to define a delectric with a gradient or with a completly user defined function based on spatial parameters. Does anybody know how to approach this problem?
Thanks and have a nice day,
Seleven.

I Seleven,
I am not sure you can do this kind of thing on CST... What about stacking multiple thin slabs of progressively changing dielectric? I suppose that it would be easy to set if your gradient is not too complex.
all the best