[UNR] Easy way to close windows in panel

I'm looking for a better way to manage my windows in UNR. I use the window list in my one panel, as I feel that's the most intuitive way to manage windows. I don't like the window selector and picker, as it is quite confusing when working with more than one Firefox windows. Is there a modified version of the window list that allows the users to quickly close unwanted windows. I have made a rough rendering of what I would prefer most. Does anyone know how to achieve this?
Thanks in advance for your help!
[attachment=0:jm60q9mb]Screenshot.jpg[/attachment:jm60q9mb]

 

Right-click on a free spot on the task bar and there you should get an option add applets. You can also use right-click to remove items. It should be relatively easy to get what you want.

 

But the problem is I don't know which applet I can use to achieve what I want..