You're supposed to place the block in the level where youd like it, and add the lights around it as normal. once you're satisfied with the lighting, save your project, 'delete everything but the lights that effect the block your turning into a map entity, and the block' then save it as SOMETHING ELSE. Build, and then load the map entity into place, in your full level.

EDIT: You can also set it to UNLIT, and change its ambient albedo.