Try this . . . this is the quick easy (kind of a pain) way, but it may work for ya. To create a filter form, someone else would have to help you out there.
In your database, go to the form you wish to search from. Once in the form, click on "RECORDS" then "FILTER" the "FILTER BY FORM", now go to the "CASE#" field you refered about, click on it and it (should) bring a drop menu down with all your case numbers, choose the one you want to work with, then go back to the toolbar and choose the "FILTER" option, then "APPLY FILTER/SORT" and Vuala, your Case# appears.
Dont forget, you may have to go back up to "FILTER" and choose "REMOVE FILTER/SORT" to view all your documents again, but play with it, and you'll get the hang of it.
To do this in code like I said someone else will have to do, if I find it somewhere I will let you know, but this will be a good start (hopefully) for you.
Good luck
Chance~