Stored Procedure Permissions With Xp_cmdshell On SQL 6.5

Is there any way to allow a user to use the xp_cmdshell extended
stored procedure without giving that user execute permissions to
xp_cmdshell in SQL server 6.5? Let me clarify. Lets say I (as the
dbo) create a stored procedure called sp_send_err:

CREATE PROCEDURE sp_send_err @CompID varchar(20) AS
declare @strCMD varchar(255)
select @strCMD = "master.dbo.xp_cmdshell 'net send " + @CompID + "
""ERROR!""', no_output"
execute (@strCMD)
GO

Now lest say I give "user1" execute permissions on sp_send_err, but no
permissions on xp_cmdshell. When I run sp_send_error I get the
following error:

"EXECUTE permission denied on object xp_cmdshell, database master,
owner dbo".

Why doesn't this work? What else can I do?