In a large bowl, cream shortening and 1 cup sugar until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in lemon zest. Combine the flour, baking powder and salt; add to creamed mixture alternately with milk. Fold in walnuts.
Pour into a greased and floured 9x5-in. loaf pan. Bake at 350° for 45-50 minutes or until a toothpick inserted in the center comes out clean. Cool for 10 minutes.
In a small bowl, whisk lemon juice and remaining sugar until sugar is dissolved; pour over bread. Cool 10 minutes longer; remove from pan to a wire rack to cool completely.