You're welcome Attila123! I'm not sure if the res agents have access to rego info of the day's flight. Its probably such a rare question that they don't know how to access that info!
Try posting your flight itinerary here and I'm sure someone (incl. myself) will be more than willing to check it up for you if possible. Do bear in mind though that any info given is subject to change, they tend to swap planes around at the very last minute.