c# Visual Studio …adding references programmatically

Question

Is there anyway that a reference can be added to a solution programmatically?

I have an add-in button, when the user presses it, I want a reference to be added. Is

Answer 1

Something like this I haven't tested it

get the environment

EnvDTE80.DTE2 pEnv = null;
Type myType = Type.GetTypeFromProgID("VisualStudio.DTE.8.0");          
pEnv = (EnvDTE80.DTE2)Activator.CreateInstance(myType, true);

get the solution.

Solution2 pSolution = (Solution2)pEnv.VS.Solution;

get the project that you want

Project pProject = pSolution.Projects[0];

add the reference

pProject.References.Add(string referenceFilePath);