Coat a nonstick skillet with cooking spray; place over medium-high heat until hot.
Add chopped red pepper, onion, and jalapenopepper; saute until tender.
Combine cornmeal and next 5 ingredients in a large bowl; make a well in center of mixture.
Combine buttermilk, skimmed milk, egg substitute, and melted margarine in a small bowl; add buttermilk mixture to cornmeal mixture, stirring just until dry ingredients are moistened. Stir invegetable mixture.
Pour batter into a 9-inch square pan coated with cooking spray.