Opt-in subscribe to Campaign monitor mailing list from Perch form

Is there a way to automatically subscribe an email address to a Campaign Monitor mailing list from a Perch form based on whether the user has checked an opt in checkbox?

Seems like the Mailchimp app allows for this: https://docs.grabaperch.com/addons/mailchimp/examples/subscription-form/

I need responses to be recorded in the Perch forms app so adding subscribers via php using a custom form won't wash. Are there any add-ons or workarounds for this perhaps using the recently introduced template filters?

Any suggestions welcome... many thanks!