使用AzMan自动测试授权方案

I have a web application that uses AzMan authorization to grant different functionality to different users. I've just started using WatiN to implement some automated web UI tests that run under Visual Studio Team System/TFS. I'd like to be able to use it to verify the different authorization scenarios. To do this though I'd need to be able to run different tests as different users who are granted differing rights through AzMan (using dummy test accounts). I have a web application that uses AzMan author