I think you’re looking for a storm door glass retainer. This does not look like weather stripping to me. Generally , weather strip goes on parts that are designed to move and need to seal (the soft black plastic around car doors). If it’s soft and pliable, it’s probably weatherstrip; if it’s rigid and inflexible it’s likely glass retainer.
I’d follow Decoy321’s advice and take measurements and pictures, then go to your nearest hardware store. But odds are they won’t have the exact match for the existing door, this glass retainer is generally unique between manufacturers and even within product lines.
You may have better luck going through a window and door installer and see how much it would be to get them to repair it, since the parts are so unique.