Hello Don,
I find your question interesting and may have started off on the same foot as you but as I think about your ask, I begin to have more questions. Perhaps more details can get us to the answer quicker. I saw the Additional resources on the right, but they don't really get us to the goal quickly. An AI response introduced me to customizing the ribbon but nothing in there about custom buttons or [links] to forms. I think our best bet is to explore Office Add-ins for Outlook. Overall, can you describe your goal in more detail? Or in a design identifying format:
"As a [type of user], when I [action], then I [expected outcome], so I can [goal]."
Best,
Andrew