Wordpress Integration Class

I need a WP expert to write a simple class to import the core functions of wordpress into a separate class inside another script. It will require a good understanding of WP global variables and everything else that is used to run WP. I need the core functions included so that I can run simple processes like registration, login and database manipulation from the external class. Basically a Bridge. Please only bid if you've done exactly something like this before, I'm a skilled PHP programmer myself but I need a WP specific guru to work this out for me. Thanks