Delphi DLL and Persistent Database Session

Has anyone had any luck maintaining a main applications database
connection in a Delphi DLL.

We have written DLL's which access an Oracle database, but the best we
have been able to do is to pass the user name and password from the
main applications session and login to another database session.

My project currently contains 51 forms and 4 other code units (Size =
1,456,800) and still growing.  The environment is Windows NT, Oracle
7.2 Database, Delphi 1.0, SQL Links, Windows 3.1, WFW 3.11, Windows

Thanks, Cooper