Cream together sugar, butter, sour cream, soda and eggs. Sift flour with baking powder. Mix together creamed mixture and flour. Add orange juice and rind. Bake at 350° for about 10 or 12 minutes. (Bake a test cookie to determine the correct time.) Use greased cookie sheet. Icing: Mix juice of 1 lemon with powdered sugar to a spreading consistency. Apply while cookies are still warm from the oven. For decoration, sprinkle a little orange rind over icing. Yields 6 dozen cookies.