Maybe not exactly what you were looking for, but it should provide you with a start:
A Resizable Graphical Rectangle[
^]
[Response to other answer]
Well, it's actually written in C#, not C...big difference. Anyway, you can download C# Express as well and build it and then add it directly. Really, though, I wasn't intending it to be the solution, but it should provide you with some direction on where to go. Chances are you are not going to find a control like you want for free. You're going to have to build it yourself.
The simple parts are the border, the mouse behavior, and the background. The more difficult parts are really the resizing and the drawing. The article above shows one way you can do the resizing, though there are other ways as well.