Combining systems

[hareshm]

I currently use Dish Network to get my South Asian Channels and Time Warner cable for all other channels. Now Direct TV has started offering South Asian channels that are not available on Dish Network. If I add Direct Tv system in my home, can I replace my 2 way RF siginal combiner with 3 way combiner and feed 2 satellite and 1 cable signal through my house cable wiring? If not what other choices do I have other then installing extra cable.

Thanks