Way to show Counter of unread posts for visited threads (on thread list)?

[Dwarden]

I wonder if there is modification, hack, template edit or else for vBulletin 4.1.10
to display
- "Counter of unread posts"
- only for visited threads
- this is shown on threads list
- it's active URL leading to first unread post inside that thread

for example see attached picture from forum which offers such feature

thanks everyone for help or tips