We had 8 Snom 760 phones, and we just added a 9th. The Snom phone has 12 programmable buttons in the middle of it. Right now, 8 of these are set to call the extension of the other users. I'm new to this, and I'm not sure how this feature was setup. How can I set the 9th person's extension on the 8 other phones? Is this setup from the 3CX console?