Right you'll need a CTI RP to CFA to VM to hit that call handler. Depending on your requirements you could use the same DN in different partitions for the call so that users who want to join would hit the DN in the partition assigned to the CTI RP to forward through unity connection. This setup would assume that only certain users would initiate the meet-me conference since they would have to be able to directly dial the meet-me pattern. It might be best if you setup different numbers but had something like *7527 as the meet-me number, and then users dial in using 7527. That would be easy for a user to remember to start a meet-me press the softkey and then dial * plus the number, otherwise just dial the number without * to join.
