string appDir = Path.GetDirectoryName(GetType().Assembly.CodeBase.Substring(8));
     //grant permission to the untrusted application
     var pset = new PermissionSet(PermissionState.Unrestricted);
     var sandBoxSetup = new AppDomainSetup
          {
               //set the ApplicationBase to a folder
               ApplicationBase = appDir,
               ConfigurationFile = appDir + "....dll.config"                                    
          };
         //create app domain
         AppDomain domain = AppDomain.CreateDomain("Sandboxed Domain", null, sandBoxSetup, pset);