Calling Oracle Function via ADO in VB 6

Using Visual Basic 6.0 and ADO, how can I call Oracle FUNCTIONS (not "procedures") within a package?  I can either use a Microsoft or Oracle ODBC driver, but I cannot use OO4O.

Versions:
Database
-------------
Oracle Version:  9i
(with 8.1.6 driver version)

Workstation
-------------
Oracle ODBC Driver:  8.1.6
Microsoft ODBC Driver:  2.573.9030
VB:  6.0 SP3
ADO:  2.5 - 2.7

No matter what information I've found on this and other forums, I've had no success in formulating the correct ADO call.  With each permutation I try, I seem to get a different error message, so I can't remember which ones I've gotten under which configurations.  The end result is always an error when I call the Execute method on the command object.

Even though I have successfully connected to the database and retrieved data using dynamic SQL ("SELECT * FROM ..."), please include specific examples from connection to the execution of the Oracle function in your answer.

The Oracle functions I'm calling have return values of type INTEGER and varying input parameters.  Here's an example of one:

FUNCTION fnAEOutcomeTypeAdd(
     p_sTypeName IN char)
RETURN INTEGER IS
     nTypeId           ae_outcome_type.ae_outcome_code%TYPE;
     sProcName     ERROR_LOG.PROC_NAME%TYPE  := 'pkgSpxLookups.fnAEOutcomeTypeAdd';
     nProcLocation ERROR_LOG.ERR_LOC_ID%TYPE := 0;
BEGIN
     SAVEPOINT BeginningOfFunction;

     nProcLocation := 1;
     select SEQ_AE_OUTCOME_TYPE.nextval into nTypeId from dual;

     nProcLocation := 2;
     insert into AE_OUTCOME_TYPE ( ae_outcome_code, ae_outcome_name)
          values (nTypeId, p_sTypeName);
     RETURN( nTypeId );

     EXCEPTION
     WHEN OTHERS THEN
          --Log the error
          pkgError.logError(sProcName,
                           nProcLocation,
                           null,
                           'Type Name='||p_sTypeName);
     --Undo the effects of this function when an exception occurs
     ROLLBACK TO BeginningOfFunction;
     RETURN (-1);

END fnAEOutcomeTypeAdd;