whenever user drag any file onto skype chat textbox then skype show right icon for that file and one custom progress bar rounded corner.

i have 4 questions

1) i am working with win application not WPF. i like to know how to develop skype like corner progressbar. i search lot google to find out skype like progressbar. so if anyone knows how to develop that kind of progress bar then please share that knowledge or give me any url from where i can download similar look progressbar.

2) when i drag any file onto my richtextbox then how could i show right icon for that file on my richtextbox. anyone can give me idea.

3) what kind of richtextbox skype use? is there any advance richtextbox library which i can use for showing picture or button etc.

4) skype shows button on chat textbox called Cancel......is it button or any image. when user click on that button then button respond accordingly. so just tell me how could place any button on my rich textbox and when i will click on that button then a event should fire at my end. any idea.

here i attach a picture from where you can see the image of progressbar that i am looking for. how i want to show the progress button and file associated icon on richtextbox. the object behind attaching the image is other person can understand what is my requirement and what i want to know.

please anyone give me the idea for my above 4 points. thanks