procedure FileUpload (Param1 in varchar2,
                      Param2 in varchar2,
                      Param3 in varchar2,
                      Param4 in varchar2,
                      Param5 in varchar2) is

  begin
    for i in ParamList
      loop
        Do something;
      end loop;

  end;

SQL> CREATE OR REPLACE PROCEDURE p (v IN SYS.ODCIVarchar2List)
  2  IS
  3    i PLS_INTEGER;
  4  BEGIN
  5    i := v.FIRST;
  6    LOOP
  7      EXIT WHEN i IS NULL;
  8      dbms_output.put_line('Parameter '||i||' is '||v(i));
  9      i := v.NEXT(i);
 10    END LOOP;
 11  END;
 12  /

Procedure created.

SQL> exec p(SYS.ODCIVarchar2List('First','Second','Third'))
Parameter 1 is First
Parameter 2 is Second
Parameter 3 is Third

PL/SQL procedure successfully completed.