The CM won't work like his old system. Why would you want it to? Sell him on the idea that he no longer needs to use codes so it is simpler than before. Since it is an analog phone, he only needs to press the recall button or a quick touch of the switch hook This puts the first caller on soft hold and gives the second dial tone so they can call anyone they normally have permissions to call, make the announcement, touch the recall button (or a short press of the switch hook) and the conference is in progress. It does not get much simpler.