Scripting

We are implementing carbon copy to helpdesk due to popular demand.  So allowing users to CC to helpdesk.  The one issue we have is of a user is an email conversation with say 7 people and one decides to CC service desk as part of the chain we then wind up with a whole bunch of duplicate tickets as a result.  Wondering if anyone has come up with a solution for this.  One might be to use mail transport rules..  but everything I come up with impacts end users and not in a good way.  

anyone tackle this with any success?