Hi Ginger, I have no specific recipe but I did see on another list at
some time a suggestion to use regular granulated sugar, grind it to a
finer powder in a blender and then mix with arrowroot powder (potato
starch may work too) to produce a powdered sugar.  As I said I have no
idea what the correct amounts would be but maybe you could play with it
if so inclined.  Good luck,

Larissa/Springfield, VA