MIX barbecue sauce, sugar, chipotle peppers and tomatoes; set aside.
SEASON steaks with salt and chili powder. Grill on medium-high heat to medium or desired doneness. Remove from heat. Let stand several minutes; cut across the grain into thin slices.
FOR each serving: Place 1/3 cup zucchini mixture on bottom half of roll; drizzle with 1/2 Tbsp. barbecue sauce mixture. Top with 4 oz. steak, 1/2 cup potatoes, additional 1 Tbsp. barbecue sauce mixture and 1 Tbsp. cheese; cover with top of roll.