First of all, the best solution would be to implement something like this:
CC is a very important thing, and unfortunately it has very weak support in zammad right now. You can only put someone in CC by the email, but still this user can track replies only by email, he can’t see them on web panel.
Good improvement would be to allow adding users in CC when creating ticket by web form, and if user is set in cc somewhere - allow him to see this ticket.
I know that it might be a lot of modifications, so in the meantime, could you at least make it possible to create overview that shows tickets where current user is set in cc and allow him to see them?
Something like here:
Looking forward for your reply.