[exim] Conditional address rewriting

Hello,

now I'm nearly finished configurating exim like I want it.
Just one point's missing: rewriting of addresses when I want.

I want to rewrite the sender's domainpart with a DC_visiblename if the
mail goes to someone who's domain is in +local_domains. But I want it to
be rewritten as DC_outside_visiblename in the other case.

Rewriting itself isn't the problem for me, but to apply rewriting to a
*sender* depending on the *recipient* is.

Any idea?

Regards,
Jürgen