You create the character in the same topic as your first one. You can make a whole new message, or you can convinetly click the 'Edit' button on the top right hand corner of your first message.
If you edit your first message, then your going to have to make a 'boost' up message that say's "So and so is new, and needs to be accepted!" If it goes for a while without being accepted, you can post a new boost message, or PM an admin/mod with the link to your character topic for them to accept it.
But! You do have to be pationt. Don't freak out if your character dosen't get accepted for a day or so ;) Admins and mods' have lives outside of CHB, too!