Is there really no way to make a ringing line appearance on another extension? I want extension 102 and 105 to ring when extension 101 rings. All are T7731 phones. I can make a DSS button but no option to make it ring? This is a basic PBX feature. I can send the call to a ring group but that screws up the recall to voicemail on a NA condition. I hope I'm the one missing something because if the TDA50 can't do something as straightforward as a ringing line appearance, that's pretty lame programming on Panasonic's end.