Show a progressbar in taskbar while form is minimized

Question

I wonder how can i accomplish the following:

I would like to display the progress of a progressbar on the taskbar while my window is minimized. See here for a visual description.

See how the icon on the taskbar gradually fills with green color following the main progressbar in the window?

Could someone tell me how to do that?

Update:

I downloaded windows api code pack and referenced it in my project and wrote the following code but nothing happens when i run my app increment the pbar and minimize:

    private void updatepbar()
    { 
        tpb.Value = progressBar1.Value;
    }

        timer1.Tick += new EventHandler(delegate { updatepbar(); });
        timer1.Interval = 1000;
        timer1.Start();

What am i doing wrong? thanks alot