Pivot & sys_refcursor

create or replace procedure test_proc_cursor(acursor out sys_refcursor) is
  l_sql1 varchar2(200);
  l_sql2 varchar2(200);
begin
  l_sql1 := '
  select *
    from (
          select extnbr,substr(rdate,1,6) rmnth,telamt from tel_tbl_cdr where rdate like ''2010%''
         )
   pivot (sum(telamt) for rmnth in (';
  l_sql2 := '''201001'',''201002'',''201003'',''201004'',''201005'',''201006'',
             ''201007'',''201008'',''201009'',''201010'',''201011'',''201012''';
  open acursor for l_sql1||l_sql2||'))';

end test_proc_cursor;