Soak corn in husks in water 15 minutes.
Cut bell pepper in half lengthwise; remove and discard seeds and membrane, and flatten pepper with palm of hand.
Set aside.
Coat grill rack with cooking spray, and place on grill over medium-high heat (350° to 400°).
Place bell pepper, skin side down, on rack; remove corn from water and add corn in husks to grill.
Grill, covered with grill lid, 15 to 20 minutes or until corn is tender and slightly charred, turning occasionally, and pepper is charred.
Cool corn.
Place pepper in ice water until cool; peel and discard skin.
Remove husks, and cut kernels from cob; place kernels in a large bowl.
Chop pepper; add pepper and green onions to corn.
Combine vinegar and next 4 ingredients.
Gradually add oil, stirring constantly with a wire whisk.
Pour dressing over corn salad; toss gently.
Serve immediately, or chill thoroughly.