[exim] relaying through different ip of the server

Hello Guys,
I am trying to relay email through different ip address bound to the
server, not only through its base (primary address).

ROUTER
lookuphost_domain_a:
 driver = dnslookup
condition = "${if or{ \
              {eq{$sender_address_domain}{test1.com}} \
              {eq{$sender_address_domain}{test2.com}} \
              }\
              {1}{0}}"
domains = ! +local_domains
ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
transport = remote_smtp_domain_a

TRANSPORT:
remote_smtp_domain_a:
driver = smtp
interface =192.168.90.214
helo_data = "I_am_from_test.com"

But doing this is OK for test1.com and test2.com only to use
192.168.90.214 ip.
I want to have a file (~/etc/eximiplist) with the mapping

virtual_domain_name:ip_address

How can I modify the above router and transport to lsearch this file
/etc/eximiplist and relay mail through its respective ip address?

Any help is appreciated.

Raj