Eureka! I think we might have a connection. Although all my Duckenfields were from Holmfirth, it is only a few miles from Huddersfield and some of them actually lived there. In any case, the Registration District for Holmfirth was Huddersfield.
Unfortunately, the St Catherine's House Index is not on-line yet, but most of the bigger libraries have the microfilms of the indexes in their Local Studies/Local History libraries. I note that you are in England at the moment, although you don't say where. If by chance you are staying with your relatives in Leeds, the main library in Leeds city centre has all the St Catherine's House indexes on microfilm although you will need to book in advance. I know because until two years ago, we used to live in Leeds and have spent many happy (but hot) hours in there!
Try emailing me on Lankylady39@aol.com as I don't want my main screenname in the public domain. I have only just adopted this so if, for some reason, it doesn't work, just post another message on the genforum and I will get back to you. If we can communicate by aol email, I can give you much more information.