How to measure Current in HFSS?

Hello guys,

I am new in HFSS right now. I designed standard primary/secondary spiral coil design for mutual inductance measurements using Lumped ports...
I successfully able to find L, M, K etc. values.....

BUT now my requirement is to get primary and secondary current plot over frequency range....
I do not know how to get Current values in HFSS.

Please help me to understand.
I tried using Current Excitation instead of lumped port but again stuck at same point....

I read on many places its not possible directly to get current values in hfss but have to use Field Calculator....is that true?Is there any other way? If not please share some information how to work on Field calculator?

Any help related to current measurement?

Thanks!

See the attached HFSS Field Calculator book. You can find the expressions for calculating current on Pg 29