Unread =/= Active
Unread = New
Now since I do not know anything about how this forum was made, I can not say what can and cannot be done here. But since 3-4 other forums I frequent have this as an option, I know for certain that it is possible to do.
If the unread already does this, then it is just how it is worded that made me never use it, because in actuality, there are more unread posts than what is listed.