C++创建.NET AppDomain 如何增加需要的Evidence？

[苏丹-陈]

我在用C#开发一个Office插件，需要添加一个C++的Shim层，但是使用向导生成的代码，创建AppDomain没有设置Evidence参数。
// Create an AppDomain that will run the managed assembly, and get the
// AppDomain's _AppDomain pointer from its IUnknown pointer.
IfFailGo( m_pCorRuntimeHost->CreateDomainEx(T2W(szDirectory),
pUnkDomainSetup, 0, &pUnkAppDomain) ); //the evidence is null.

如何使用C++实现下面的Evidence？
AppDomainSetup setup = new AppDomainSetup();
setup.ApplicationBase = AppDomain.CurrentDomain.BaseDirectory;
SecurityZone zone = SecurityZone.MyComputer;

// Set up the Evidence
Evidence baseEvidence = AppDomain.CurrentDomain.Evidence;
Evidence evidence = new Evidence(baseEvidence);
//evidence.AddAssembly(typeof(MergeAction).Assembly);
evidence.AddHost(new Zone(zone));

_appDomain = AppDomain.CreateDomain("AddIn AppDomain", evidence, setup);