1. Either you truly want to develop .NET program in C++. For this, you need to create a CLR-based C++ project. It looks like that you have created a C++ project for native code, because the "Add Reference" dialog does not look right. In CLR projects, it will also offer you additional tabs, such as .NET, COM, Browse, Recent. Create a new project, and make you select some of the templates under Visual C++ -> CLR.
2. Or, you want to use our components from C++ code compiled into native instructions - in such case, do not use "Add New Reference"; instead, learn from the examples supplied with the product. One of the options is to place #import directive into your code, which will create wrapper classes for the QuickOPC-COM type library.
I have a problem to add the reference of OPCLabs.EasyOPC.DataAccess in Visual Studio 2010 C++. In the properties menu of the project, there is a reference line. I clicked on and in references struct, I clicked on Add reference but there was only project page without reference to add.