[Solved] How to create output variables in CST?

Dear all,

Is it possible to process results in CST just like how we can use output variables in HFSS?
For example, in HFSS I can define a new variable called 'ratio' which I specify as S21/S31. I need this because I'm running an optimizer in CST for antenna design.

Any help would be greatly appreciated.
Thank you.

Edit: Managed to find it. Can be done by using 0D template based postprocessing, mix 0D results