Parametrize a detail

Ian Johnson
edited June 2020 in BricsCAD BIM

I have looked at all of the videos to do with the above title as well as the help file and still cant seem to find what I am looking for.
I have attached a drawing file that I want to save as a detail that enables me to have different size support beams and different size incoming beams. The connection plate needs to be the same and the same distance down from the top of the beams.
I assume this is possible using a parametric detail and I am trying to achieve this (unsuccessfully).
Any clues?

thx