[otrs] Allow owner to be changed in reply to customer

I am trying to encourage our "front-line" agents to let customers know whenever a ticket has to been transferred to another agent. At present, the change of ownership is accomplished via a note, which is not emailed, so the customer does not see it. Is there any way to make the "owner" field available in the AgentTicketCompose window? Are there other ways that people have accomplished this? Hugh