Different Opacity and Reflection Maps ?

Hi All,
is it possible to load a different map for Reflection?
I realize the opacity will be taken from the alpha chanel of my .bmp file
but I would like a different map for reflection.

to be specific - I need a windshield to be 90% transparent and 25% reflective while the body of the car is
opaque and barely reflective.

thanks for any help.
J. Anderson