how to make light not affect lightmapped mesh

How do you make new lights to not affect lightmapped mesh? The only way I can do this is by duplicating a light that was used for lightmapping, because those lights are automatically “unlinked” to the mesh after lightmapping. So, how do you do it with new lights placed in the scene? Thank you in advance.

ah silly me, I found out about culling mask. sorry!