My oval dual line direct tv satellite is currently wired to direct its signals to one direct tv tivo plus 2 standard receivers in a total of three rooms. A perfect vision 3 X 4 multiswitch channels two lines to the Tivo with the remaining two lines going out to the two standard receivers. I wish to replace one of the standard receivers with a second Tivo unit but apparently need an additional line to take advantage of the Tivo's full capacity/features. No antenna.cable signal is connected at the present time. How should I proceed?