I'm gonna show you how to edit a '.ctt' file using notepad, and add or delete contacts email addresses all you want.
1) Goto Your contact list.
2) Click on Contacts(menu) and then click save contact list...
3) When you save it change the '.ctt' to '.txt'.
4) Open in Notepad or any text editing program. (Now you see all your contacts and a bunch of xml blah stuff.)
5) Delete or add the contacts you want.
6) Then save it as '.ctt'. (ex: my contacts.ctt)
7) Go to the messenger accound you want to put these contacts in.
8) Click on Contacts(menu) and then Import contacts from file.
Then you're done!
PS: I don't care if you already knew this, this is something I found out myself.