Per-unit-length resistance and inductance extraction

Hello,

I have the following question.
Does anybody have any ideas how to extract per-unit-length resistance and inductance using 2D-mesh in COMSOL?
I don't know, how should I excite my conductor, so it will give me the needed parameters.

For example, I have a circular cross-section cable, made from copper. I want to extract resistance and inductance as function of frequency (per-unit-length), using only 2D-mesh of my cross-section.