I have a CIX 100 I'm trying to program so that CO line five can only be accessed by one extension, and that line only rings at that same extension. Right now if an incoming call on that line is not answered it starts ringing another extension, even tho it doesn't have that line assigned to a button. The intercom button starts to flash and the phone rings. On the old Toshiba systems you could assign which extensions had access to individual lines in program 40 but I can't find that option in the program cross reference materials between the new and old systems. Any help would be greatly appreciated