The account expiration date can be set 90 days after the current date using:
csentry("accountExpires").Value = Date.Now.AddDays(90).ToFileTime
or based on a value in the Metaverse:
csentry("accountExpires").Value = DateTime.Parse(mventry(DateKey).Value).ToFileTime().ToString()
Setting the accountExpires attribute to 0 or to 9223372036854775807 means no expiry.
By: Paul Loonen