gmail api tool to export emails who are CCed

I have a lot of people who email me at my gmail account with ".mil" email addresses.

I want to create a tool where if I have received an email from someone with a ".mil" email address, I can export all the other emails CCed or addressed to me with ".mil" emails.

Think of it like this... I want to generate a list of all the "passive" people with .mil email addresses - they do not need to have ever needed to write anything to be apart of our export.

thanks,