Hello Sir, I am outlook plugin developer (vsto). I understood your requirement . I will follow following steps in plugin: 1->Will give a custom button in Outlook composer meeting window. 2->When user click in this button it will call Rest/Web api and get response 3->Response will be inserted in to meeting body then user will be able to Send the meeting to recipient Please correct me for any step if I am missing anything Let me know ,
here is right fit .