Here's another alternative, in the newsgroup score file have the following
lines:
-1 pattern from: $
2 from: rick
This would mark as read all the messages in the group and show only rick's
posts.
The advantage to this approach is that any articles that reference his
post are still there in the news group and readable by either scoring the
thread or by pressing enter to enter the group and view all the read
messages. Sometimes, a post is meaningless unless you read it in context.
Also, the group would still be subject to the expire runs and save you
from having a humongous folder.