How to add a static current in Electromagnetic wave transient study

Hi,

I am working on a problem using electromagnetic waves transient module. I want to study the interaction between incident EM waves and an annulus conductor in which a static current is flowing on it.

It is easy to set up the incident EM waves using scattering boundary condition. My question is how can I establish the static current in the annulus conductor?

I can establish a static current in AC/DC module, such as the MEF study by putting a voltage difference on the two ends of the conductor. But it seems in electromagnetic waves transient study I can not define a voltage on the conductor end.

Any comment would be highly appreciated.

Zhang