execute immediate problem

[steeve123]

SQL> create or replace procedure test_steeve is
2 begin
3 execute immediate 'host notepad';
4 end;
5 /

Procedure created.


SQL> execute test_steeve;
BEGIN test_steeve; END;

*
ERROR at line 1:
ORA-00900: invalid SQL statement
ORA-06512: at "DEMO_320.TEST_STEEVE", line 3
ORA-06512: at line 1




Is there restriction on host command in procedure?