How do you add "Employee-id" in ad user's property tab.

[sx3]

I have configured a stand alone 2003 test server with exchange installed. I imported users from the live server to do some testing.
Does any one know how to add "Employee-id" to the user property's tab?
I tried the following but the script but didn't work:

http://www.mcpmag.com/columns/article.asp?EditorialsID=1062

Any help will be greatly appreciated.