dynamically generated nav bar

I am using Flash 8 for a web site and the client has asked me to build a nav bar in the image gallery that looks like this:

http://www.capitalwebtec.com/clients...nd-gallery.jpg

Here is the catch...The number of images will be determined by the client and they will put that number in a text file that will reside on the server. The nav bar has to build itself dynamically by pulling in the thumbs from the server (they will be named in sequence). So the pics have to come in externally, plus the number of pics has to be able to change each time the file is loaded.

There will only be four thumbs displayed at a time, but I have to set it up so that you can rotate through as many as there are by clicking on the arrows on the left and right side of the nav. Is this clear? I have no idea where to begin building this dynamically.

Help!

Thanks,
Brian