I'm struggling with this one. How do people add in lintels/steel/beams, in this case a Catnic CG90/100 for a cavity wall?

I feel I should be adding this detail in 3D or should I just draw it in 2D over my section cut in the view map.
I've looked through the Beam tool and the Import Standard Steel Profiles and the closest I could find was a Z shape under EuroCode. But it's not right. On the
Catnic site they have BIM models but they are all in .rfa (Revit) format, no idea how you get that into ArchiCAD for OSX users. They also have DWG files but each time I've tried to import in ArchiCAD 20, even with the import scale set to mm, it's not the correct scale. The only success I have had is using Sketchup to save the DWG to SKP, open that in ArchiCAD 20 and copy/paste into the working plan.

For future UK Catnic lintel needs should I follow a 'Complex Custom Profile' tutorial, assuming that this would allow me to start adding in the dwg/profiles and manufactures specs so I can insert this as a 3D object next time? Unless there is a UK plugin I not seen...
I just not sure how to tackle next time without using something like Sketchup, unless that is a typical process.
Thanks