SQL & PL/SQL :: How To Use Bind Variable

I have the below cursor 1 which is working already.For my requirement i want to use bind variable like second cursor.But its telling Bind Variable "p_col_list" is NOT DECLARED.

How to use bind variable Here.

Cursor1:
DECLARE
emp_cv sys_refcursor;
iid NUMBER := 1;
i_sql varchar2(100);
p_col_list varchar2(2000) := 'aaa,bbb,ccc,ddd';
BEGIN
i_sql := 'select '''||REPLACE(p_col_list, ',', ''',''')||''' from dual '||CHR(10) ;
dbms_output.put_line(i_sql);
OPEN emp_cv FOR i_sql ;
END;

Cursor2:
DECLARE
emp_cv sys_refcursor;
iid NUMBER := 1;
i_sql varchar2(100);
p_col_list varchar2(2000) := 'aaa,bbb,ccc,ddd';
BEGIN
i_sql := 'select '''||REPLACE(:p_col_list, ',', ''',''')||''' from dual '||CHR(10) ;
dbms_output.put_line(i_sql);
OPEN emp_cv FOR i_sql using p_col_list;
END;