Use the & System::DelphiInterface::& to access the underlying interface pointer. Care should be used with this System::DelphiInterface::&, because it provides no reference counting support. For example, when using this System::DelphiInterface::& to programmatically replace the underlying interface, you must first call Release to decrement the reference count of the current interface and, depending on whether you are using this as an additional interface reference, you may need to increment the reference count on the interface being added.