Obtaining a Court order for information

[selfhelp]

I have an ongoing dispute re: a relative's estate. I have obtained medical records and there is information within the medical records that would throw doubt on a.n.other's version of events. If we can disprove this version of events then we can put forward coercion. However the information we need will be held by a third party who the other side have an account with. Naturally we can not approach the third party and request and as far as I am aware I would have to go to court to request an order for the third party to turn over the information. I can only find references to court order's in relation to child maintenance and marital matters. Please could someone advise as to how I would obtain a court order to obtain the information and what court form I would use along with any template wording. Many thanks in advance