[exim] MajorDomo and Exim

Hi all

    I running Exim 4.5 (2 Instances and MailScaner) and i want that all my
MajorDomo Mailinglist activities will go throw diffrent IP address
    Rather than my Main IP address of the syste (i have 10 IP address on my
machine  eth0:0 eth0:1 and so on..

    For that issue i have added 3rd Exim process which listen   on diffrent
IP  and i have configure the remote_smtp
    to bind diffrent IP when issue SMTP connections.
    And it also use diffrent spool directory.         (Everything works
fine)

    Unfortenatley i dont know how to tell majordomo to use that 3rd exim
instance 
    Insted of using the regular Exim which use my base IP Addr.

    I am looking for suggestions ...

    Meanwhile i have opened the majordomo.cf file and found the following.
    unfortenatley i tried change the sendmail_command to /usr/sbin/exim  -C
/etc/{diffrent config file}  but it doesnt work

# $sendmail_command -- Pathname to the sendmail program
#                      usually /usr/lib/sendmail, but some newer BSD systems
#                      seem to prefer /usr/sbin/sendmail
#
$sendmail_command = "/usr/sbin/sendmail";
$mailer = "$sendmail_command -oi -oee -f\$sender";
$bounce_mailer = "$sendmail_command -oi -oee -f\$sender -t";

Best regardS