Combine first 6 ingredients (cornmeal through black pepper) in a bowl; stir well. Combine buttermilk and egg white in a bowl; stir well. Dip oysters in buttermilk mixture, and dredge in cornmeal mixture.
Coat a large nonstick skillet with cooking spray, and place over medium heat until hot. Add oysters, and cook 3 minutes on each side or until browned.
Cut bread loaf in half horizontally, and spread Creole Mayonnaise evenly over cut sides of bread. Arrange lettuce and tomato slices over bottom half of loaf; top with oysters and top half of loaf. Cut loaf into 8 pieces. Serve immediately.