Hi Oli,
Thanks for your question and detailed scenario!
You have a couple of options on this scenario, but it will require some development instead of just implement the tool there.
1- Copilot for Microsoft 365:
With this AI tool, you could get data from meetings, documents or any other information internally via Microsoft Graph capacity, then take actions from the data you have.
In this option, you already have the AI option connected with your Microsoft 365 environment but if you need to customize anything (as you mentioned you will need this), you could integrate the Copilot Studio actions, conversational, plugins or Cloud flows to do it.
2- Copilot Studio only
With Copilot Studio you could build copilots for your organization and take actions via Power Automate cloud flows and use actions if needed.
Then to use the "Create generative answers" connected with your meeting transcript to respond the user's questions.
In general, you have a lot of things to do. Let me know if you need anything else.
Regards,
Renato