Modify Excel ribbon ui in runtime

Question

Is it possible to instantiate a Microsoft.Office.Interop.Excel.Application and then modify the ribbon by C# and finally load some workbooks which may be accessed by callbacks to C# from these ribbon controls?
To be a bit more specific, I want to do this out-of-process from a WPF or similar application.

Id so, please hint to some code to getting started.
(All I have found involves using VSTO which I cannot use for certain reason, which most important is that I cannot be stuck with the old "full framework", .Net 6 compatibility is mandatory, further I dont want the workbooks or Excel installation to be modified in any way ragarding the ribbon

I mean just modifying volatilely ("in memory") which is gone after Microsoft.Office.Interop.Excel.Application.Quit() and thus only useful for the lifetime of the Microsoft.Office.Interop.Excel.Application object.