Passing Data into Drupal – And using it.

Hello, I’m playing around with Drupal 7. I have found a way via PHP script to interface with our existing web site. (the PHP script gets the login info, and logs them in, starts drupal).

What I also need to do is pass in some session info, like Customer and Region as these will be needed to dynamically create url’s later.

How can I pass in and later retreive this information?


Drupal version: