Help with ISAM data access

We are using an ISAM database, it is called RTISAM and has been in place for many years. We access the data using AIX code and using FORTRAN programs. I have heard that there are ways to access this data via Visual Studio and C# with the use of either a FORTRAN dll or an ODBC driver. I'm somewhat of a dummy here, because I can't for the life of me figure out how to make a connection to this database, which lives on the Unix server. Has anyone ever successfully integrated an ISAM database with a Windows program (or .NET)?

It sounds like you are a windows client. If you can get odbc working, you have many clients like excel data import. Usually, you need a driver, a host and port for tcp connectivity, an id, password and sometimes a schema/db name. I see products out there, like easysoft, usually very offordable:
ISAM ODBC Driver
http://www.datamystic.com/datapipe/odbc_vendors.html

Have you used any of these products? I was looking at EasySoft earlier as well. The problem is that the database is actually not just one file system...for example, we have many clients and each client has, for instance, a database containing their employee information. That database is stored in that client's directory on the Unix server...but, if I can get ODBC working, and even different instances of a connection string, I'm not sure I would know how to have windows (i.e. my own windows program developed via visual studio) access the Unix directory structure. Like I said, I'm a bit of a dummy here - just got out of school and know all the new stuff, but not how to integrate new with old, if you know what I mean.