How to create a dynamic parameter in a Framset

Hallo everyone, I am biginner in Axapta and X++. Perhaps someone can help me out. This is the scenario: Our Webshop is put in an Frameset. The topframe is generated by a ContenManagement-System. In The URL to the topframe is an Parameter like this: In this Case the German page is shown. How can i use a dynamic parameter in this frameset to set the Language from the customors Language id from the CustTable?? How can i acces the FrameFile?? Thanks and Greets