Actionscript 3 :: One Way Deep Linking In PureMVC?

A project requirement is that it be 1 way deeplinkable(a specific query string will load a section within the swf).I have a URLProxy that I use for all external linking. It makes sense to me to put the query string logic in this proxy. So in the constructor, I check for a querystring, and then send a notification if it equals a predefined value.One problem with this is that I'd like to predefine this query string key value I am checking against in an external xml file. So another proxy, loads-parses this config xml, then the URL proxy checks against this.