FUNCTION WP19DUMMY(vname IN VARCHAR2) RETURN SYS_REFCURSOR 
IS
tmpcur SYS_REFCURSOR ;
BEGIN
  OPEN tmpcur FOR SELECT IVALUE FROM GENPARAMS WHERE NAME = vname;
  RETURN tmpcur;
END WP19DUMMY;

SELECT WP19DUMMY('TD') FROM DUAL;

WP19DUMMY('TD
--------------------
CURSOR STATEMENT : 1

CURSOR STATEMENT : 1

IVALUE
-------------
            0

SQL> create or replace function f (vname in varchar2) return sys_refcursor
  2  is
  3    tmpcur sys_refcursor;
  4  begin
  5    open tmpcur for select * from emp where ename=vname;
  6    return tmpcur;
  7  end;
  8  /

Function created.

SQL> var c refcursor
SQL> exec :c := f('KING')

PL/SQL procedure successfully completed.

SQL> print c
     EMPNO ENAME      JOB              MGR HIREDATE                   SAL       COMM     DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
      7839 KING       PRESIDENT            17/11/1981 00:00:00       5000                    10

1 row selected.