Cream together the butter and sugar and beat in the eggs. Add the baking powder and salt to the flour and mix alternately with the milk; then add the grated lemon rind, the cherries, and walnuts. Bake in a loaf pan for 1 hour in a 350 degrees F oven. Mix together ½ cup white sugar and the juice of 1 lemon and pour over the baked loaf in the pan. Let stand for 10 minutes.