Alternately, you can use VRS.
12-07 - Name your Modes
12-08 - Set to switch modes 1/2 with LED on
22-02 - if POTS, set lines to Normal on Mode 1, VRS on Mode 2, if BRI/PRI/SIP set to DID
if BRI/PRI/SIP - go to 22-11, set entry 1 as indial, target IRG 1 or whatever you want for your day ring assign, for 2nd mode, go to table 201, set to 502 or whichever VRS message you want to use
Go to 22-13, set mode 1 to 1, Mode 2 to 2, mode 3 to 3, and so on
25-02 - Set mode 1 to VRS message 1, Mode 2 to VRS Message 2 and so on
25-06 - Set your AA options
25-03 - Set mode 2-8 as 0, prevents people ringing phones when office unattended