[exim] Help with received_header_text

Hello,

I am trying to find out a solution to rewrite a little piece of a header for
privacy and security reason. I do not want to remove the complete header as
it is used for loop detection.

To be clear and precise, I would like to change:
from:

Received: from 200-100-10-10.reverse.fqdn.tld ([200.100.10.10]
helo=ClientPC)
to:
Received: from {SERVER_RDNS} ([{SERVER_IP}] helo={SERVER_NAME})

I believe this has to do with received_header_text. All example always
include authentification which I do not want to include in my case.

Can anybody lighten me? Also, where should I place the condition?

Thank you.

Vladimir