isolate part of issue and set it up as reporter

[joris raffin]

Hello, 

in my JSM i'd like to get an email which is part of a comment of templated issues to set the mail as the reporter. It shows like this : 

Bonjour,

Le compte test@test.fr est en attente de validation.

Veuillez le vérifier et déclencher le processus de validation.

Ceci est un email automatique.

I think it is possible with advanced rules with JSON but i don't know how i can reach like the 19th letters or how to isolate the mail. the body of the issue is always the same so I think there is a way to get it. 

note : the title of the issue also contain the email.