Creating C# wrapper for C++ DLL Exporting 20 C++ classes with virtual methods and abstract classes

I have C++ DLL of both x64 version and x86 version, which exports 20 C++ classes which contain probably 500 methods in total in all the classes. All the classes have complicated inheritance with abstract classes and pure public virtual methods in the base C++ class, and only the abstract classes are exported, but any of the virtual methods in the base abstract classes are not exported due to the C++ nature. I need to a developer to write a C# wrapper to access all of the C++ classes. I will need to use the C# wrapper under both x64 and x86 running mode. I will need to write C# class to extend the native C++ class. I will also need to access types like std::vector, std::vector, std::string from my C# code through the wrapper. It is a VC Compiled native C++ DLL exporting C++ Classes instead of a C style DLL exporting global functions. You won't be able to use P/Invoke Assistant to create interface for the C++ classes. I have only the native C++ DLL of both x86 and x64 version and all the required header files. Again, It is NOT C style DLL. It is a C++ DLL containing C++ classes. Writing a C# console testing application is required to test all the interfaces of the C# wrapper library, both under x86, x64 mode.