Use Send Alert. In "To other emails" you can enter any other email addresses.
You can also use a {{lead.token}} (or any token) there, but you need to be in a Trigger Campaign context for that to work. (A Batch Campaign that calls Request Campaign on a Trigger Campaign is fine.)
OK, so it sounds like I can create a local token and add the email addresses in the token instead of having to copy and paste 55 emails in the "To Other Emails" section.
Thanks, will give it a go!