[Exim] SMTP AUTH and relay

Hello !


I have an exim(3.22) mailserver for internal and external mail running.
But I've got to dial in to my ISP.
Some mailservers (for example AOL) don't accept mails from a
dynamic IP, others blocks via RTBL's.
I have a Provider where mails can be relayed. But only with pop
after smtp, or smtpauth.
How can I setup, that special domains (readen from a file....) relay's
via my relayer and do a smtp auth / pop after smtp ?
Where can I find some howto's ??

Thanks 
    Lars