hi!!
you can extend the miles as well!!
from the swissair intranet (info posted in this thread...)
http://www.flyertalk.com/forum/Forum40/HTML/000185.html
Extension of Expiry Miles
Some members might ask in advance for extension of miles going to expire by the end of the current year.
Extension of Miles prior to the Expiry Date is not permitted. The only way to action such a request is to wait until Miles have been expired and then to re-credit the same again to member’s account!
regards
nitin