Hi,
IMO the best way to put microwave structures in a design is to assign the critical blocks to a footprint..
Not too long ago I wrote simple script to convert DXF LWPOLYLINE rectangles and CIRCLE entities to a footprint. If you are working with Keysight ADS - the script was written against its DXF exporter. If not, probably any DXF exporter will do:
Even better, I read the latest nightly builds include custom shape pads capability. probably best to use that one.