Message header rewrites on hub servers?

Morning,

I've been asked if its possible for Exchange to rewrite message headers on emails to a specific address and forward them on to an external address adding the original recipient as an additional custom header for a third party to use. I've done some research on this these articles talk about message header rewrites but on an Edge server. I don't have an edge server, only hub servers as i route the mail out to a smart host (Ironport). I know its possible to rewrite the headers on the smart host but the question was posed can it be done at exchange level instead?

Thanks for any help in this...

http://www.msexchange.org/articles-tutorials/exchange-server-2010/management-administration/using-header-rewriting-exchange-server-2010-service-pack-1.html

http://technet.microsoft.com/en-gb/library/aa996806(v=exchg.141).aspx

.: Lister :.