[Exim] Adding headers after SMTP AUTH

Hi!

I would like Exim to add header specified bellow to any outgoing message,
sent by authenticated user:

        Recieved: ..blablabla..
                 (Authenticated as [ldap_user])
                  ...blablabla

,where ldap_user is user authenticated using:

login:
  driver = plaintext
  public_name = LOGIN
  server_prompts = "Username:: : Password::"
  server_condition = ${lookup ldapdn{\
            user="cn=${quote_ldap:$1},ou=members,o=mycorp" \
            pass="${quote_ldap:$2}" \
            ldap:///o=mycorp,\
                    ou=members,\
                    cn=${quote_ldap:$1}} {1}fail}
  server_set_id = $1

I've tried with:

received_header_text = "Received: \
          [...]
          ${if def:authenticated_sender {(AuthUser=$authenticated_sender)\n\t}}\
          [...]"

But it won't work...

Any simple ideas? :)

Cheers,
Pawel

--
Pawel Wilk <siefca@???> - Poland.com sa -
1024D/FF0D20A9: 3B4A 55BA B502 9C4D D7ED 5643 BC7C F62D FF0D 20A9