Roberto Bozzolo -
It's not possible to save thread sorting options on a per thread basis. However, you can change your view to always sort newest to oldest so the new ones are always first in the list.
In your profile, there is an option to "Automatically Jump To The First Unread Message In A Thread." This option works well when the threads are sorted newest to oldest or oldest to newest. However, it has problems finding the right message when the view is sorted by threading and the discussion spans multiple pages.
The subject of the message has [NEW] at the end of it if you haven't read it yet which is your visual indicator that it is the new message in the thread.
Long story short, I think I understand the feature you are looking for and have tried to give you some suggestions on what you can do today to accomplish it. I will add your feedback to the other requests on this topic and hope to get a better solution for you.
Thanks for the feedback!
Molly K.
Web Support & Operations Manager
National Instruments