I have never done this before, but from reading I think what I want is a hotline. We have a handicapped door and want to put a phone outside that will ring only to our reception so the door can be unlocked for the person wanting to come in. We are looking at using simply an analog phone in a weatherproof box. How would I program this so that the person outside would simply lift the receiver and it would ring to the desk - and the phone would not do anything else. Thanks.