Sometimes remembering or deriving the full distinguished name of an object in the directory can be painful to do by hand. Luckily, Microsoft provides a nice little browser utility with the server os' and the 2003 admin pack. Beware that you can do A LOT of damage with the utility, so, my recommendation is to use standard user credentials when binding - you could delete a nice chunk of the directory tree without much effort!

So, open up the utility (start>run>ldp), and then goto File>connect, and up in the FQDN of the domain you want to bind to (e.g. mycompany.local). Next, goto File>bind, and put in some domain credentials - stadnard user ones are more than enough and highly recommended! The third step is going to View>tree, and then just press OK. If you're in a large domain, you might want to specify the DN of a root to cut down on DC load.

Now you can browse to the object you need the DN of. Find it, and double click. On the right, if you scroll up a bit, you'll find all the object's attributes, including it's DN. Highlight it, press Ctrl + C, and paste it in whereever useful