Write some software

Conference Bridge With Raise Hand Feature in Asterisk / FreePBX. I need for a client as follows; Number to call in, reaches announcement with instructions. Then goes to conference line where an instructor and moderator are talking. No one else can talk (everyone else muted). All the rest of the callers in the conference that are listening should have an option to press a DTMF key, that basically raises hand and that places the caller in a queue but DOES NOT pull them out of the conference ONLY when the operator in the queue is available (not on a call). Needs someone with extensive Asterisk development skills and need to have basic FreePBX skills.