If you can't do this with standard objects (I would not be surprised if you can't - but I don't use the standard GS library), then you will need to look at 3rd party windows.
The problem with that is your signature shows version 19, so you may not be able to find 3rd party addons now for that version and usually these addons will cost $$.
You will probably be better of just creating a custom window yourself (unless you need many different windows).
https://helpcenter.graphisoft.com/user-guide/88767/#XREF_93670_Saving_Rectangular
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11