Bring sugar, water and lemon juice to a boil in a heavy saucepan, over medium - high heat, stirring to dissolve sugar. Let syrup boil for 1 minute. Set aside to cool after it becomes clear. CAKE: Preheat oven to 350~. Combine flour, baking powder and salt. Set aside. Cream butter and sugar until fluffy. Beat in eggs one at a time. Mix in coconut and lemon rind. Gently blend in flour mix, alternating with milk, beginning and ending with flour. DO NOT overmix. Pour into a buttered 15-1/2" x 10-1/2" x 1-1/2" baking pan. Bake in center of oven 25 minutes, or until cake shrinks away from sides of pan. Place on a rack. Pour cooled syrup over hot cake. Let cool. FROSTING: Cream together cream cheese and butter until smooth. Blend in sugar and vanilla. Beat until smooth. Thin frosting with milk until it falls in a heavy ribbon from a spoon. Drizzle in a heavy random pattern over cake, leaving some open spaces on surface of cake.