getting the monostatic RCS in CST

I'm having trouble figuring out how to generate a monostatic RCS in CST Microwave Studio. The Broadband RCS plots in Template-Based Postprocessing are definitely not that, but it's unclear from the manual what exactly they are. The Farfield macro "Calculate Monostatic RCS" doesn't work, possibly because I don't have an I-solver license.

I want to simply know the monostatic RCS as a function of frequency at the source. I'm using a plane wave excitation with the Transient solver, and I alter the source direction from run to run, so the M-RCS should move with the source.

Any help would be appreciated. The manual is rather thin on how to set things like this up.