In a bowl, mix the brown sugar in the hot water until dissolved. Pour into a large resealable plastic bag, and mix in wine, soy sauce, olive oil, garlic, and lemon pepper. Place salmon in the bag, seal, and marinate 8 hours or overnight in the refrigerator.
Preheat a grill for high heat.
Lightly oil the grill grate. Reserving marinade, place salmon on the grill, and cook 5 to 8 minutes on each side, or until easily flaked with a fork.
Transfer reserved marinade to a pot. Dissolve the cornstarch in cold water. Bring the marinade to a boil, and stir in cornstarch mixture to thicken. Serve over the salmon or on the side as a dipping sauce.