How Can I Sample LightMass Volume Lighting Directly?

In a platformer, I have an overhead spot light attached to my character. I would like to change the brightness of the light depending on the ambient lighting the character is in. It makes sense to me to grab the lightmass light probe calculation for my character as a a good approximation of the local lighting conditions (nearly all our lights are static). Is there currently a way to do this, be it from blueprint, C++, or the material editor?