Wordpress Plugin - Iframe Dynamic Height Adjustment

I need a worpress plugin that can dynamically adjust the height of a iframed site. The plugin must be able to get the height of a page based on a marker div and adjust the iframe height from there. Shortcode must be used. I will retain all rights to the plugin. Full payment will be paid after completion and successful testing of the plugin. The website being iframed is a php driven membership script (I don't own the source code). The only thing I can change is the html template the page is rendered on.