I work on ph lines everyday for my business, it shld plug straight in and it cannot damage your telephone line, or the 12 volt line cannot damage it...
....all standard phones work on 12volt 2 pair.
Inside your home line, there are 4 wires, 1 x pair is blue-white, the second pair is red-black.
Blue and white is usually your first phone line.The second pair is for your second ph line, if u want one etc.
Plug it in.no big deal. provided it has the standard socket, it shld work easily.take a photo of the plug n send it to me if ya want...i can tell ya in 3 seconds.

Thanks Cave
                   I plugged it in with the existing Cord in the bedroom socket but got nothing never had a phone in there so might have been the point.   So unplugged the cord for the internet and plugged it into the inside of the phone and it works Comes up telstra payphone but says cashless calls only it will take the money but wont let you call out.  Maybe thats the pulses the telstra guy was talking about?  I rang home form my mobile and it rang and answered but it was to hard to talk to myself and listen at the same time lol