TOPIC: Ability to assign registrants in an event to a mailchimp grp

I have events in different cities. I want different email lists for the events in the different cities. At present the mailchimp plugin requires you to add everyone from every event into the same group.

I would like the ability to set which group each event is directed to -- so I can mail my different event seperately or in combination, just by checking a box on mailchimp when I send out my emails.