I was able to successfully create a process to DISABLE LOGINS rather then
Expire Accounts Here is a QUICK Snipped

I am useing VS 2005

I Added a Refference for GWCMB1.DLL (AdminTypeLibrary)

Dim objGWSystem As New AdminTypeLibrary.System

Dim objGWUsers As AdminTypeLibrary.IADUsers

Dim objGWUser3 As AdminTypeLibrary.IADUser3


objGWUsers = objGWSystem.Users

objGWUser3 = objGWUsers.Item("testuser","PONAME","DOMAINNAME") 'Note
testuser is the samaccountid

objGWUser3.DisableLogin = True


Grantted I am useing Groupwise 7.0.3 so I haven't backward tested this but
for those that may be intrested.