exclude/include raytracing

Is there a way to have an object reflect into material A but not in material B? (A &B being reflective materials).

I know you can set the reflectivness of an object in its properties, but this illumination cardboard object is intended to be only reflected in one specific material (thousands of little mirrors), but shouldn’t be reflected in the floor, of course…
Any hints?

For the record, i’m stuck to Vray 1.09 for this job. (I know .. I’m lagging)

vray doesn’t have individual include/exclude material based properties like the old max raytracer does.