Hoe to reply to a selected or opened mail in outlook from excel

Hi all,
I have created a template to reply to emails that works very well.
Now I try to find out if it is possible to reply from the same template to a selected email in outlook in order to keep a control over the conversation history.
I've seen several things but I don't understand it and I don't know how to put it into practice.
I attach the document.
Thank you,
Jose