[exim] Trying to block by Reply-To/From headers match

Hello,

I am willing to block messages containing certain patterns in
From:/Reply-To: containing certain pattern.

I tried first blocking by senders: test configuration contains (right
below "begin acl"):

--- configuration snippet below
acl_check_sender:
   deny    senders = /etc/exim/sender_reject.list

accept
--- configuration snippet above

and the mentioned /etc/exim/sender_reject.list contains

user@???
*@example.net
*@example.org

To block "user@???" and all senders from example.net and
example.org domains.

As far as I understood, the above only filters by the address reported
in "MAIL FROM" SMTP command (i.e., by Return-Path), which can be bogus.
How do I do correct filtering by Reply-To:/From: (using From: only if
Reply-To: is missing)?

--
Sincerely,

Konstantin Boyandin