Show decal under specific light

Hello! I want to make this decal:
image
Seen under the light:


How can I do this? Any models, scripts, or plugins I can use?

As far as I have looked, I have not found any discussion about this.

Just insert a point light into the object, this will light up your object.

What I mean is, keep the decal NOT visible but when the light is shined over the decal, it will show up.