Preheat the oven to 350°, and grease and flour your bundt pan
In a large bowl, combine the cake mix, pudding mix, water, eggs, rum, and oil. Beat the mixture on low for about 30 seconds, then on medium for about 2 minutes. Now, stir in the pineapple, and transfer the batter to the prepared pan.
Let this bake for 45 minutes or until a toothpick inserted into the center of the cake comes out clean.
Cool in the pan for 15 minutes, before transfering it to a wire rack.
In one of the small bowls, mix one cup of the confectioner's sugar and pineapple juice. Then brush the mixture over the warm cake with a pastry brush. Now allow the cake to cook completely.
In another bowl mix the remaining confectioner's sugar, rum, and cream of coconut. Then drizzle this over the cake. sprinkle with coconut.