Hello Andre,
thanks for the description. I can follow the steps using another planning until choosing "Layout for controlling" in the tree. However I do not see any steps any further to cause the "...requires SAP GUI for Windows" message.
In general, having no OLE SDK available, SAP GUI for Java can neither talk to MS Office components via OLE Automation, nor can it embed such a component.
However what works in general, is to transfer files from the system to the Mac and open then in a MS Office application.
I would assume, that SPRO needs the one of the former OLE based features.
Best regards
Rolf-Martin
P.S. JavaGUI 7.40 is available from SAP GUI Family page.