So u have a DLS modem and want to share the connection with ur house network ?
If yes then it's simple. RJ11 phone cable goes into the DLS modem and RJ45will come out of the modem which u need to connect to ur router to share the connection. U have to do the proper setting in ur router though, so that it can do the proper dial up with username and password.
If no, let us know clearly what is ur intention for the need to convert.