Adding Parameters to Zend_Navigation

I have a problem with Zend_Navigation that I am hoping for a little guidance on.

I'm in the process of adding a Zend_Navigation to a legacy app as described [here on SO].1

The thing that I am not sure of is how to add parameters to the navigation menu after the data is loaded from the xml file.

What I want to do is get 2 identifying parameters from the url and add them to the Zend_Navigation so that they are included in things such as the breadcrumb bar, so that if a user selects the previous item in the breadcrumb they are returned with the correct params in the url.

The parameters, I believe need to be set at the Action lev开发者_如何学JAVAel rather than the controller.

Any help would be appreciated.

Many thanks.