How can I cast dynamic shadows from a light without rendering the light itself?

Hello, I am working on a game where the main character can control the shadow. For this, I am using a spotlight parented to the character which can be controlled by the player, which in turn, controls the direction of the character's shadow. However, I don't want the spotlight itself to be rendered during the game. Is there any way to achieve the effect? I am using Unity 5.0.1f1

Any help would be highly appreciated.