Courts index documents by assigning a number to each case. That number has digits to specify the court that is handling the case (and whether it is a municipal, county, state or federal case), the year it was filed and to differentiate it from other cases. If the local county court is not handling the case you are inquiring about, that court's clerk probably has the resources at his disposal to tell you where the case originated. If not, you can do the rest of your sleuthing online. According to the National Center for State Courts, the ability to search by case number or docket number online can vary by individual county websites.
Visit the local county court office and show the case number to the clerk. It is important to start at the county court courthouse, not the local city, town or village court, because county is part of the state system. With one glance, the clerk should be able to tell you if the number you have is not part of the state system. She should also have a guide for identifying codes from other counties.
Check the website for your state's unified court system. It should have links to county courts and a contact number of someone who can help you navigate through the system. Enter the docket number into the search field to see if it brings up reports, files or abstracts from a specific court. If not, a contact person listed on the site may be familiar with jurisdictional identifiers.
Check the federal judiciary's Public Access to Court Electronic Records system (PACER). This site allows searches by docket or case number. You can search every federal criminal, civil and bankruptcy court by case or docket number. There should also be phone numbers listed for district court clerks to aid in your search.
The case number is usually located near the top of the document. The name of the court is typically identified throughout the document and is stamped and dated by a court official.