How do I customize the default Outlook E-Mail Message Form - O365?

I would like to have a form pop up when I create a new email message or reply to a message in O 365. The form would have 3 optional fields, and the user would complete as many of the fields as desired, and then press a next button. This would bring the user to the "normal" message form with the subject line filled in by a concatenated version of the completed fields in the form.

This is my concept of what I need, but I would accept any workable solution that gets me to where I want to go, which is a standardized subject line for a construction company for which most emails have the following subject line information:

Job Name  -  Wintergreen
Lot #  -  201
Subject  -  Drywall will be delivered on July 18, we will begin working July 19

My end result would look something like this in the actual subject line of the message:

Wintergreen-201-Drywall will be delivered on July 18, we will begin working July 19

Any ideas on this would be appreciated.