torment, it appears you're asking someone to learn what has to be done (i doubt too many people in the world will just know how to do it) and then take the time to teach you.
I suppose someone here may have the time to do that to help you. I know that if I had to do it, first I'd read up on the exim.conf file, then figure out which commands, try them on a testbed system, and make notes of all I did until I came up with the proper functionality.
One hour? three? ten? I have no idea.
Your thread was open for a week with no answer, presumably because no one had anything to suggest. I'm sorry if my simple suggestion upset you; that was not my intention.
And I'm sorry I don't have all the answers; I'll leave the thread open and perhaps someone else will.
Jeff