Calling member method on unmanaged C++ pointer from C# (I think)

Question

I apologize in advance if this is a trivial question... I'm pretty C++ / unmanaged dumb.

Here's a simplified analog to my setup:

--In myUnmanagedObject.h in DLL:

class myUnmanagedObject
{
     public:
          virtual void myMethod(){}
}

--In MyControl.h in Assembly #1:

#pragma make_public(myUnmanagedObject)

[event_source(managed)]
public ref class MyControl :
    public System::Windows::Forms::UserControl

{
public:
   myUnmanagedObject* GetMyUnmanagedObject();
}

--in C# in Assembly #2:

unsafe
{
    MyControl temp = new MyControl();
    myUnmanagedObject* obj = temp.GetMyUnmanagedObject();
    obj->myMethod();
}

I get a compile error saying that myUnmanagedObject does not contain a definition for myMethod. Assembly #2 references Assembly #1. Assembly #1 references DLL. If I compile the DLL with /clr and reference it directly from Assembly #2, it makes no difference.

How, from C#, do I execute myMethod ?