[exim] Please help me with a Exim router condition

Hi everyone,

I wish to use a "condition =" for my router section which should evaluate to true if either of $sender_address_domain or $original_domain exist in the file /etc/mydomains.

Tried a lot of permutations & combinations using "if", "forany", "lookup" etc. but just can't figure it out. Any help is appreciated.

Regards,
Sam