So dc will work ac wont, as mdg stated.
If the light is AC just use a power inverter and that will make 120 AC out of 12v. DC.
http://www.amazon.com/s/ref=nb_sb_ss...power+inverter
This will give you an idea of what we're talking about. The one I use has wires with alligator clips already on. The 400's have clips and a liter plug-in.