I would advise you to do it the Drupal way, i.e., create a custom module. If you're developing with Drupal, you may as well learn to do this.
You will find a lot of free Drupal tutorials here:
http://codekarate.com/daily-dose-of-drupal
Creating a single page is fairly easy. You will need to look at hook_menu. Download the examples module and look at the Menu examples go create a simple page.
Create a subfolder in your custom module to hold the Big Blue Button files and try calling your php script from your menu callback function.
If you've never done this sort of thing, it may seem daunting at first, but have a try & you will find out it's not that difficult.