o.k., thx fr info, luxx.  poser reflection node has softness channel.  0 (black) = no softness, whilst 1 (white) = alotta softness, but can go higher than 1, implying I would invert your glossy map.  can then use fresnel shader with {reflection, specular} and diffuse nodes as inputs to fresnel blend node.  if using shader in above img with diffuse channel, would have to violate fresnel's law.

T would dig it - doubles as knuckle-duster