create table abc
(internalid varchar2(20),
vCol1 varchar2(20),
nCol2 Number,
dCol3 date,
vCol4 varchar2(20)
);

Insert into ABC
   (INTERNALID, VCOL1, NCOL2, DCOL3, VCOL4)
 Values
   ('11112', 'bbbb', 102, TO_DATE('05/02/2015 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 
    'yyyyyy');
Insert into ABC
   (INTERNALID, VCOL1, NCOL2, DCOL3, VCOL4)
 Values
   ('11111', 'aaaa', 101, TO_DATE('05/20/2015 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 
    'xxxxxx');
COMMIT;

create table abc_param
(id varchar2(20),
 source_col varchar2(200)
);

Insert into ABC_PARAM
   (ID, SOURCE_COL)
 Values
   ('111', 'VCOL1');
Insert into ABC_PARAM
   (ID, SOURCE_COL)
 Values
   ('222', 'NCOL2');
Insert into ABC_PARAM
   (ID, SOURCE_COL)
 Values
   ('333', 'DNCOL3');   
COMMIT;

DECLARE 
    TYPE empcurtyp IS ref CURSOR; 
    c        EMPCURTYP; 
    emp_rec  abc%ROWTYPE; 
    stmt_str VARCHAR2 (2000); 
    --e_job emp.job%TYPE; 
    dml_str  VARCHAR2 (200); 
    z        VARCHAR2 (200); 
    vparamid VARCHAR2 (200); 
BEGIN 
    vparamid := '11111'; 

    stmt_str := 'SELECT * FROM abc WHERE internalid = :1'; 

    -- in a multi-row query 
    OPEN c FOR stmt_str USING vparamid; 

    LOOP 
        FETCH c INTO emp_rec; 

        EXIT WHEN c%NOTFOUND; 
    END LOOP; 

    CLOSE c; 

    dbms_output. Put_line ('aaaa = ' 
                           || emp_rec.internalid 
                           || ' --- ' 
                           || emp_rec.vcol1 
                           || ' -- ' 
                           || emp_rec.ncol2); 

    FOR i IN (SELECT * 
              FROM   abc_param) LOOP 
        --z := emp_rec.[i.SOURCE_COL]; --This part i want to ask the code .... 
        dbms_output.Put_line (i.source_col 
                              || ' = ' 
                              || z); 
    END LOOP; 
END; 

C:\>type t.sql
col cols new_value cols noprint
set feedback off
select listagg(source_col,',') within group  (order by id) cols from abc_param;
set feedback on
select &cols from abc where INTERNALID = &id;

SQL> @c:\t

Enter value for id: 11111
VCOL1                     NCOL2 DCOL3
-------------------- ---------- -----------
aaaa                        101 20-MAY-2015

1 row selected.

SQL> @c:\t

Enter value for id: 11112
VCOL1                     NCOL2 DCOL3
-------------------- ---------- -----------
bbbb                        102 02-MAY-2015

1 row selected.

FOR i IN (SELECT * 
              FROM   abc_param) LOOP 
        --z := emp_rec.[i.SOURCE_COL]; --This part i want to ask the code .... 
        dbms_output.Put_line (i.source_col 
                              || ' = ' 
                              || z); 
    END LOOP; 

C:\>type t.sql
col cols new_value cols noprint
col nb new_value nb noprint
set feedback off head off
select 'case
'||listagg('when line = '||rownum||' then '''||source_col||' = ''||to_char('||source_col,')
') within group  (order by id)||')
 end' cols,
        count(*) nb
from abc_param;
set feedback on
select &cols
from abc,
      (select level line from dual connect by level <= &nb)
where INTERNALID = &id;

SQL> @c:\t

Enter value for id: 11111
VCOL1 = aaaa
NCOL2 = 101
DCOL3 = 20-MAY-2015

3 rows selected.

SQL> @c:\t

Enter value for id: 11112
VCOL1 = bbbb
NCOL2 = 102
DCOL3 = 02-MAY-2015

3 rows selected.

SQL> create or replace procedure p (p_val in number) is
  2    cols varchar2(1000);
  3    nb   pls_integer;
  4    res  sys.odcivarchar2list;
  5  begin
  6    select 'case
  7  '||listagg('when line = '||rownum||' then '''||source_col||' = ''||to_char('||source_col,')
  8  ') within group  (order by id)||')
  9   end', count(*)
 10    into cols, nb
 11    from abc_param;
 12    execute immediate
 13      'select '||cols||'
 14       from abc,
 15            (select level line from dual connect by level <= :nb)
 16       where INTERNALID = :id'
 17    bulk collect into res
 18    using nb, p_val;
 19    for i in res.first..res.last loop
 20      dbms_output.put_line (res(i));
 21    end loop;
 22  end;
 23  /

Procedure created.

SQL> exec p(11111)
VCOL1 = aaaa
NCOL2 = 101
DCOL3 = 20-MAY-2015

PL/SQL procedure successfully completed.

SQL> exec p(11112)
VCOL1 = bbbb
NCOL2 = 102
DCOL3 = 02-MAY-2015

PL/SQL procedure successfully completed.

CREATE OR replace PROCEDURE P (p_val IN NUMBER) 
IS 
  cols VARCHAR2(1000); 
  nb   PLS_INTEGER; 
  res  sys.odcivarchar2list; 
BEGIN 
    SELECT 'case     ' 
           ||Listagg('when line = ' 
                     ||ROWNUM 
                     ||' then ''' 
                     ||source_col 
                     ||' = ''||to_char(' 
                     ||source_col, ')     ') 
               within GROUP (ORDER BY id) 
           ||')      end', 
           Count(*) 
    INTO   cols, nb 
    FROM   abc_param; 

    EXECUTE IMMEDIATE 'select '||cols||'         from abc,              (select level line from dual connect by level <= :nb)         where INTERNALID = :id' bulk 
    collect 
    INTO res 
    USING nb, p_val; 

    FOR i IN res.first..res.last LOOP 
        dbms_output.Put_line (Res(i)); 
    END LOOP; 
END; 

/