Put Auth Code button on any set. Call it Ext 123.
Assign Auth Code to ADJUNCT, call it 223, and use 223223 as an auth code (that's one way)
At 123, press auth code button, dial 223223, you will get dial tone, dial *33 tel number #. You should get confirm tone.
OF course 223 has to be able to do RCF. But, you knew that.