Display Top Categories of all Stores in Navigation Menu

Hi, I have Magento 1.6.2 installed and have a setup of different Stores. Right now I have only displayed the top category and subcatetories of the current store on each store as navigation in the frontend/base/default/template/catalog/navigation/[login to view URL] But I also would like to have listed all top categories and subcategories of the other stores. It should be just a simple top navigation, where all top categories of each store is listed horizontal in one line and if you hover over each top category or subcategory it shows the subcategory or subsubcategory. Is it possible? Would be great if someone could help!