How can I change the subject in response emails?

[Tigger]

Hi!

I would like the subject of my response emails to look like this:

RE: Ticket Title [Ticket Number]

Got the "RE" and the ticket number in there. Don't know where to set the ticket title, though. As a default OTRS sets the subject of the first customer mail as subject, but that is not necessarily the ticket title (we often have to change the title to something more indicative for our developers).

Thanx for any help!