Immerse and soak the plank in water 1 hour; drain.
Combine syrup, Cointreau, and rind in a small saucepan; bring to a boil. Cook until reduced to 1/4 cup (about 3 minutes). Cool 5 minutes. Sprinkle 1/4 teaspoon salt and 1/8 teaspoon black pepper over fish; brush fish with syrup mixture.
Place plank on grill rack, and grill for 3 minutes or until lightly charred. Carefully turn plank over, and place fish on charred side of plank. Cover and grill for 12 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness.
Combine remaining 1/4 teaspoon salt, remaining 1/8 teaspoon black pepper, orange sections, avocado, orange juice, onion, bell pepper, chives, and lime juice in a medium bowl; serve with fish.
Wine note: Salmon works with many white wines (and even some reds), but when the nutty, woodsy flavor of a charred cedar plank is factored in, I'd serve a California chardonnay. It, too, has nutty woodsy flavors, and a creamy, citrusy chardonnay will also mirror the creaminess of the avocado and the citrusiness of the orange. Try Geyser Peak Winery Chardonnay 2005 from Alexander Valley, California ($13). --Karen MacNeil