LightDir doesn't work with baked light

I realize this may not be a bug, but the documentation on the LightDir node doesn't mention that this node won't work with baked lights. I spent well over a month making some shaders that rely on the LightDir node, and now when it came time to bake my scene, I got whammo'd by the fact that the LightDir nodes aren't working. The docs should probably should warn that that will happen. Is there some alternate way to get the light's direction when using fully baked lights?