[exim] feature request: set authenticated

Hi

I would ask you about you opinion about a new feature request:

I would like to do the following:

warn host = a.b.c.d
       set authenticed = test

So that remote hosts can be authenticated directly.

I know, I can do all this using $ack_cX, but I have a lot of rules, all of
them using authenticated already and I can check this easier.
The only change needed in exim would be to allow "set" to set the
authenticated variable, which in turn could be any variable.
This would make exim even more powerfull.

Small change. Big possibilities?

Your 2 cent?

Regards,
Steffen