@mitchino, I am not sure how exactly we should understand your request, but as far as I understand you simply want a light to be visible in reflections, but not in scene illumination (direct, indirect lighting).
Right now I do not have C4D installed temporarily, but here is an example in 3ds Max. You have an "emit light" checkbox in the Corona Light Mtl, and it will make the light visible in reflections, refractions, and directly, but will remove any illumination. Note that this is possible for the Corona Light Mtl, but not for Corona Light objects. Another solution that would do exactly the same thing would be using a Corona Mtl with self-illumination enabled, and nesting it inside a Rayswitch Mtl with the GI slot empty.
Another question is whether you want the reflections of that light to be visible on the surface of all scene objects, which are reflective, or in a single object/material only. The latter would be much more tricky to set up.