Substituting ground red pepper for dried red peppers
I'm not sure if this works for cooking, but I use this method for oil or vinegar infusions: Get empty tea bags at the local tea or kitchen supply outlet. If the peppers are cayennes, put 1/2 teaspoon of ground cayenne per pepper into the bag(s), tie off securely, and use in your dish. Fish the bag(s) out at the appropriate time. Yes, grinding a pepper produces more than 1/2 teaspoon of ground pepper, but ground pepper has much more surface area than whole peppers, so you need to scale your ground pepper back to account for that. If the peppers are hotter than cayennes (habaneros, ghosts or reapers), cut back the powdered amount more. If they are mild, such as bell peppers or sweet pimentos, use 3/4 to 1 tsp of powder per pepper.