How many _conductors_ (individual wires, not cables) are in the existing switch box, not counting any bare (ground) wires? If there's only two, you might be out of luck unless you can get a wire to the existing light...

And your new house doesn't happen to be in Western Maine, does it? :P

There are three whites that are connected together by a wire nut. There are two blacks and a pig tail connected together by a wire nut. The pigtail goes to the lower terminal on the switch. There is a black that connects to the top terminal on the switch. I believe there is an always on receptacle and the switched ceiling & flood lights that get power from the same source. The flood that I want to put on a separate switch is wired directly to the ceiling light.

No, I am not in Maine. I am in 80 degree Texas.

Replace the exsiting switch with a new double box or use a double switch that fits into a single box.
Bring your light cable into the switch box.
Add another pigtail and attach your new switch.
Connect the light white into all the other whites.
Connect your light black to the other terminal on the new switch.

Thanks, that is what I thought. Glad to know I had it figured out correctly. Now one other question since I will have 4 white 12 gauge wires in one wire nut. Is there a trick to getting all of them together and in the box. In the past when I have used 12 gauge wires getting them wired in a wire nut and in the back of a box has always been difficult.

You might need to change to a larger box.
4 white, 4 blacks, 1 ground, 2 for switch = 24.75 cubic inches required + any internal clamps.