applicationphysicalpath

ApplicationPhysicalPath in silverlight

Hi guys, string str = HtmlPage.Document.DocumentUri.AbsoluteUri; gives me http://localhost/MyApplication/Pages/Silverlight/SLMain.aspx but I just need the ApplicationPhysicalPath - in asp.net I can do HostingEnvironment.ApplicationPhysicalPath to do that, but I don't know how to do that for silverlight. Any hints? Thanks, Voodoo ...