Subtitution Feature

Hi, i want to use feature in legacy Pbx such as Alcatel called Subtitution. By pressing prefix code (feature code) and enter my extension number to particular phone and then that phone belong to my extension number. If i want to exit just enter feature code and my extension number then the phone back to orginal/previous extension number. Is it possible to do on FreePBX? How to do that? Because i tried to using feature code user login and logoff but doesn’t work. Maybe that for different purpose. Tks.