Sounds like he had a reference to the MS Access Object Library.
In VB6, you can add it by going to Project > References... > Microsoft Access [version] Object Library
To access a database, you'd create an Access.Application object
Code:
Dim app As New Access.Application
...and use the various methods within to open the database and do whatver you need.
If you're doing any type of Access stuff, I'd recommend that you use ADO instead.. much cleaner and easier. That can be found by adding the "Microsoft ActiveX Data Objects [version] Library"