I have a customer that is a small medical office with 7 analog lines. They have a CXii with Embedded Voicemail and 6900 phones. Line 4 is a private line that rings on 1 phone. They dial 9 to call out, but want to know what they can do to specifically dial out on line 4. I thought maybe they could just dial the trunk number to dial out but that does not work. What is the easiest way to accomplish this?