Is there any way of recording orders made on a non-Drupal website?

I'm thinking of calling (e.g. through an XMLHttp call) a Drupal page with the order details in the URL, such as: www.drupal-domain.com/AddOrder?SKU=483&email_address=joe@blogg.com
This will create a new order for the specified product

I need this so I can use the Affiliate module to track payments across two websites, only one of which is a Drupal one

Note: I checked the existing Ubercart modules and support forum and haven't been able to find anything

Does this exist?

Thanks,

Coen