A plug in type is what I have in my NID here, its a Siecor ADSL POTS Splitter, i forget the model number. But it comes with a plug and socket wire. You plug the plug into the test jack, which brings the raw telephone line directly into the splitter. You plug the wireing blocks wire into the new cable from the splitter. Correct then, you dont have to move the voice wires at all, they remain where they are on the wireing block. The splitter then has the terminals for your DSL circuit, which in this case is the raw phone line (after its going through some fuses in the splitter.)
Either way, Im sure there are other styles of splitters out there, but they all do the same thing, block the DSL signal from the voice circuit. (Technically known as a low pass filter.)