Preheat oven to 350°F. Combine flour, baking soda and salt in a bowl and set aside. Mix sugar and margarine in large bowl until combined. Add eggs, one at a time, blending well after each addition. Add banana, yogurt, rum and vanilla. Beat until blended. Add flour mixture and beat at low temperature until moist. Stir in coconut. Spoon into a 9x5 loaf pan coated with cooking spray. Sprinkle with additional coconut if desired. Bake at 350°F for one hour until toothpick inserted comes out clean. Cool 10 minutes in pan and then remove to rack to completely cool. Combine icing sugar and juice and drizzle over warm bread.