Getting the layered navigation and toolbar ouside Magento

Im trying to get the layered navigation of a category links from a php that is outside magento.

I can create all of the category html, but the problem is that the layered links are created with the params of frontcontroller (at the same way of the toolbar links).

If i have a filter selected the creation of layered links doesnt take account of it, and also the layered links havent the category url...

I try to recreate the frontcontroller of the category page inside magento on my php ouside that, but i haven success... Even i recreate the $_SERVER, but the controller seems to not find a router...

In the php if i use mage::run, it do the operation of calcule correctly but mage::run makes the response and isnt i want because i need an xml output only of layered navigation.

If i use mage::app i can get the category html, but the controler isnt calculated correctly although is the same $_SERVER[request_uri] and havent correct links. The front controller havent action...

In the frontcontroller request i see two differences: in magento dispathed is true, but in the php no, and in magento de request_uri are rewrited to catalog/category/view/id/7?color=99 while in the php not hombre.html?color=99

Im missing anything, i need to initialize the front controller? o reinitialize???

Or there a different way to get the layered navigation from outside magento??