The best you could do is to submit the progress of the progress bar to the server via an AJAX call. On the server have a graphics library (e.g. ImageMagick, GD) dynamically recreate the progressbar image using the coordinates you give it. This would really become overkill though, and my gut feeling tells me that there is a better solution for you than dealing with images.
Let me know what your goal is and maybe I can suggest something better.