I'm not completely sure about the particular attributes you are trying to access...
But Autodesk has stopped adding things to the COM API. You might have a lot more luck if you switch to a .NET language, so you can use the .NET API.
Also, Microsoft has deprecated VBA and is strongly encouraging its partners to stop using VBA, so you can expect support for VBA to start decreasing rapidly across the board. These days, everything Microsoft is trending in a .NET direction. So switching to a .NET language will also position you better for the future.
-- Sinc
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Sinc