Is parameter in ORDER BY clause possible?

Question

I'm using a function to return a ref cursor and currently pass a parameter without any problems. I would like to change the sort on the fly by passing a parameter to the order by clause, but Oracle ignores it.
CREATE OR REPLACE PACKAGE pkg_agent_appt_status AS
TYPE rcur IS REF CURSOR;
FUNCTION f_agent_appt_status (ssn IN VARCHAR2, sort_str IN VARCHAR2) RETURN rcur;
END pkg_agent_appt_status;
CREATE OR REPLACE PACKAGE BODY pkg_agent_appt_status AS
FUNCTION f_agent_appt_status (ssn IN VARCHAR2, sort_str IN VARCHAR2)
RETURN rcur
IS
retval rcur;
BEGIN
OPEN retval FOR
SELECT agncy.CORPORATE_NAME "Agency Name",
agnt_state.APPT_STATE "State",
agnt.AGENT_STATUS "Appt Status",
TO_CHAR(agnt_state.APPT_STATE_EFF_DT,'mm/dd/yyyy') "Effective Date",
agnt.AGENT_NUMBER "Agent ID",
agnt.AGENT_STATUS "Agent Status",
STATE.STATE_NAME
FROM AGNT_APPT_STAT_PRDCR_WRK agnt,
AGNT_APPT_STAT_WRK agncy,
AGNT_APPT_STATE_STAT_PRDCR_WRK agnt_state,
STATE
WHERE agnt.AGENT_TAX_ID = ssn
AND agnt.COMPANY_CODE = agncy.COMPANY_CODE
AND agnt.PARENT_AGENT_AGENCY_ID = agncy.AGENT_NUMBER
AND agnt.COMPANY_CODE = agnt_state.COMPANY_CODE
AND agnt.AGENT_AGENCY_ID = agnt_state.AGENT_AGENCY_ID
AND agnt.AGENT_NUMBER = agnt_state.AGENT_NUMBER
AND agnt_state.APPT_STATE = STATE.STATE_CODE
ORDER BY
sort_str;                     
RETURN retval;
END f_agent_appt_status;
END pkg_agent_appt_status;

Answer 1

If you want to do this, you'd have to use dynamic SQL (execute immediate or DBMS_SQL). For the easier 'execute immediate' approach, you'd do something like
create or replace someProc( someArg varchar2 )
as
  strSQL varchar2(4000)
begin
  strSQL := <<string containing your SQL statement up to the order by clause>>
  strSQL := strSQL || 'ORDER BY ' || someArg
  execute immediate strSQL;
endJustin