SQL & PL/SQL

Hello Experts,

I have created a Pipe lined function with execute immediate, due to below requirement;
1) Columns in where clause is passed dynamically.
2) I want to know the data stored into above dynamic columns.
3) I want to use it in report, so I don't want to insert it into a table.

I have created a TYPE, then through execute immediate i have got the query and result of that query will be stored in TYPE.
But when calling the function i am getting
ORA-00932: inconsistent datatypes: expected - got -

Below is my function and type, let me know i am going wrong, and is my logic correct.

CREATE OR REPLACE TYPE OBJ_FPD AS OBJECT
                  (LOW_PLAN_NO VARCHAR2 (40),
                   FPD VARCHAR2 (5),
                   SERIAL_NO NUMBER,
                   CEDIA_CODE VARCHAR2 (2),
                   DT DATE);
----                                      
CREATE OR REPLACE TYPE FPD_TBL_TYPE AS TABLE OF OBJ_FPD;
----
CREATE OR REPLACE FUNCTION FUNC_GET_FPD_DATE (P_LOW_PLAN_NO    VARCHAR2,
                                              P_CEDIA_CODE     VARCHAR2,
                                              P_SERIAL_NO      NUMBER)
   RETURN FPD_TBL_TYPE
   PIPELINED
AS
   CURSOR C1
   IS
          SELECT 'FPD' || LEVEL TBL_COL
            FROM DUAL
      CONNECT BY LEVEL <= 31;

   V_STR        VARCHAR2 (5000);

   V_TBL_TYPE   FPD_TBL_TYPE;
BEGIN
   FOR X IN C1
   LOOP
      V_STR :=
            'SELECT A.low_PLAN_NO,
           A.FPD,
           A.SERIAL_NO,
           A.cedia_code,
           TO_DATE (
                 SUBSTR (FPD, 4, 5)
              || ''/''
              || TO_CHAR (C.low_PLAN_PERIOD_FROM, ''MM'')
              || ''/''
              || TO_CHAR (C.low_PLAN_PERIOD_FROM, ''RRRR''),
              ''DD/MM/RRRR'')
              DT FROM ( SELECT low_PLAN_NO, '
         || ''''
         || X.TBL_COL
         || ''''
         || ' FPD, '
         || X.TBL_COL
         || ' SPTS, SERIAL_NO, cedia_code FROM M_low_PLAN_DETAILS WHERE NVL('
         || X.TBL_COL
         || ',0) > 0 AND SERIAL_NO = '
         || P_SERIAL_NO
         || ' AND cedia_code = '
         || ''''
         || P_CEDIA_CODE
         || ''''
         || ' AND low_PLAN_NO = '
         || ''''
         || P_LOW_PLAN_NO
         || ''''
         || ') A,
           M_low_PLAN_DETAILS B,
           M_low_PLAN_MSTR C
     WHERE     A.low_PLAN_NO = B.low_PLAN_NO
           AND A.cedia_code = B.cedia_code
           AND A.SERIAL_NO = B.SERIAL_NO
           AND B.low_PLAN_NO = C.low_PLAN_NO
           AND B.CLIENT_CODE = C.CLIENT_CODE
           AND B.VARIANT_CODE = C.VARIANT_CODE
CONNECT BY LEVEL <= SPTS';

      EXECUTE IMMEDIATE V_STR INTO V_TBL_TYPE;

      FOR I IN 1 .. V_TBL_TYPE.COUNT
      LOOP
         PIPE ROW (OBJ_FPD (V_TBL_TYPE (I).LOW_PLAN_NO,
                            V_TBL_TYPE (I).FPD,
                            V_TBL_TYPE (I).SERIAL_NO,
                            V_TBL_TYPE (I).CEDIA_CODE,
                            V_TBL_TYPE (I).DT));
      END LOOP;
   END LOOP;

   RETURN;
EXCEPTION
   WHEN OTHERS
   THEN
      RAISE_APPLICATION_ERROR (-20000, SQLCODE || ' ' || SQLERRM);
      RAISE;
END;

Waiting for your views.

Regards,