Gmail : URL to reply to specific email conversation

Question

In Gmail, I have a link to an email conversation : https://mail.google.com/mail/u/1/#inbox/FMfcgzGmvpJWZJvzHpvrqbTnZgrfHTlg I would like to generate a link that would :

• open this conversation
• click on "reply to all" in the last email of the conversation
• add a specific message in the body.

If not possible with a link, maybe this could be solved with javascript? Here's the context (simplified) :

• We have a google spreadsheets where we would paste links to emails in the 1st column.
• In an 2nd column we have some data
• In a 3rd column, we generate messages depending on the data of the 2nd column.

=> I want to open the link in a new window, reply to the last email and paste the content of the 3rd column in the body.

Would this be possible ?