add users to local administrators

From: Techpro (ahmadmuhm@myway.com)
Date: 01/28/03 

From: "Techpro" <ahmadmuhm@myway.com>
Date: Tue, 28 Jan 2003 03:37:55 -0800

I have a situation that my helpdesk support needs to have
full access on some client workstation in one domain and
not to any servers.
now they are members of domain admins which is very bad
security implementation.
I need to add some of my AD users to the local
administrators group on some workstation
Please any help of that
I searched Technet /Script Center but no script for that

Thanks for Help