Address a page/post in a WP-based Facebook app

We use a WP-based site as a Facebook App.
Let's assume that the app (homepage of the WP site) has the address http://www.facebook.com/artagenda/app_208195102528120 which displays the content of https://fb.artagenda.com/ in the App canvas.

With what additional parameters can we address a (sub)page for display in the App canvas directly? (based on permalink or post id)

Thank you & best regards, abstractus