home phone question

[mtg]

okay so i have 2 lines in a office at my house and the second line is only in there and i want to hook up a two line system in another room but i need a adapter that will be like power over Ethernet but i can't thank of what is called for rj-11 i need it to plug into the wall and the second line plug in there and then i plug the second wall adapter in the other room and bam second line now in both rooms you may also know it when you use satellites that require a phone line