hi dorothy,
first this is the actual site i went to,
http://www.col.statistics.gov.uk,
registered/login, then filled in relevant info,and payed by card, and they do the rest,ie sent the cert, but they do make a small charge even if they cant find what your looking for,
but if your not sure on ordering thought the site ring the phone number i posted, the southport one, and the people there are very helpful, even if you havent got index numbers, etc..
good luck with your search
regards yvonne.