I'm making a custom add-in for Outlook 2013/2016 and decided to implement it with a custom ribbon button. I've followed this guide which has been good so far : https://timdams.com/2017/05/09/how-to-create-a-simple-outlook-vsto-addin-a-step-by-step-guide/
The add-in simply edits the "location" field of a new meeting request or appointment and inserts a pre-defined phone number (for a conference call etc).
I've got that part working with the click of a custom button in the ribbon, but the inserted phone number is hard coded. I'd like to make it customizable and create another button that brings up a "settings page" where a user can enter in their own phone number, save it, and then the add-in will use that number instead.
I'm having trouble finding resources on how to do this. If someone could point me in the right direction that would be great.