Hi Colin, welcome to the forum.I think you need someone with a full Ancestry membership to help you with this one, to get access to the Warwickshire birth and Christening records, as the standard BMD doesn't start this early.I'm not sure if you join on a free 2 week trial you can get this info, maybe worth a try. You could also try familysearch.org, its free and they sometimes have earlier records.
Good luck, Sue