Lighting – Unity point light turns into lightmap

I'm developing a puzzle with a bullet with cracks. Inside the balloon, there is a bright spot. Its light rays emerge from cracks and strike some platforms (walls / ceiling / ground).

To solve the puzzle, the player must rotate the balloon to match the light coming out of the cracks with a pre-lit pattern on the platforms.

I do not know how to make the pre-illuminated pattern. I do not want it to be done manually using a texture editing tool like Photoshop or GIMP. I remembered that it could probably be done using light cooking. I think what I need is to turn the light from this point into a lightmap and use it only on those platforms, but I do not know how to do it.

Can someone help me with a solution?