Light reflections

Hi
I'm trying to find an efficiant way of calculating simple reflactions - using GH
sun as a point - reflection from any number of surfaces (flat) so it can be mesh
fron a center point on the surface (just one)
and then get the reflection vector
i thing i can get all of the data - vector - surface normal at a certain UV
and the math formula ..... (Specular reflection - wikipedia)
my aim is not to get render engine out of GH just get some vectors for start...
so my question is - how to built vector based math in GH
Thanks
Tamir