CST - How to plot Boresight error w.r.t antenna scan angle in CST MWS?

Hi...I have designed and simulated an antenna, and I have the radiation pattern & other E-field, and H-field plots. Also, I designed and simulated the same antenna, but it is now enclosed by a radome. I have its radiation pattern as well as other field plots. Now, I need to obtain the boresight error plot for different antenna scan angles in a single plot. Can anyone suggest how to proceed with it in CST Studio Suite   MWS? Please help me out with this problem. Thank you.