Two interdependent studies - but I cannot use results from frequency domain study as input for stationary study

Dear all,

How can I use the result from a parametric (parameter 'b') sweep-frequency domain study (e.g. emw.Ez(b) ) in another function defined under Definitions (e.g. f(emw.Ez(b)) ) which is used as an input for a stationary study?

According to the results that I am getting, what is actually passed to the second study is ZERO.

Could you please send me a reference?
Or tell me how to shall I input the results from a study to another study?

Thanks a lot!