This guide demonstrates how to create a new project in Microsoft Visual Studio for a new APSIM model.
In Visual Studio, create a new project of type “Class Library”. Uncheck the “create directory” box.

Add a reference to CSDotNetComponentInterface.dll and CMPServices.dll to the project (Right click on References in the Solution Explorer, click the Browse tab and navigate to the DLL.
Also add an existing item to the project: Model\CSDotNetComponentInterface\EntryPoints.cs. Make sure you use the "Add as link" option at the bottom of the window:
Save the solution, project and class file name.
The Solution Explorer should look like this: