DSL line??

OK, Here goes….I have a DSL line put in our warehouse, but the GREAT phone Company would only put the DSL line RJ11 jack in a room where the phone stuff is. I need to make a cable that will let me move the modem to another room ( about 100 ft.) The phone people tell me I can use standard phone cable to run the line from the jack to the modem. SO can I use CAT3 cable to make the cable and how does I set the wires for the RJ11????