Pass a validation before adding to mailchimp list

Is it possible for the plugin to check a field first before an entry moves to the list? I have this RSVP form asking if the one filling it up can attend, cannot attend, and can attend but might not make it. I’d like the ones who answered “can attend” (and only those) be added to my mailchimp list.
…or do i need another plugin for that?
Thanks.

https://wordpress.org/plugins/contact-form-7-mailchimp-extension/