SQL & PL/SQL

hi all,
I am using oracle 10g. i am new to procedures.
What i want is i can hide column by using SET HEADING OFF; in sql*plus.
But what i want i need to do this using procedure. not with sql command.

I wrote this procedure:

SQL> create or replace procedure SP_PROC
2 as
3 qry varchar2(30);
4 begin
5 qry := 'set heading off';
6 end SP_PROC;
7 /

Procedure created.

SQL> BEGIN
2 SP_PROC;
3 end;
4 /

PL/SQL procedure successfully completed.

This executed successfully but when i executed select statement the columns heading is not hiding.
when i do SET HEADING OFF; this it is getting hide. but i need to through procedure. Because from my front i can execute procedures not simple set commands.
Any help please urgent.
Thank you.