Create a Visual Studio project programmatically

Question

As my question say I want to create a new project based in a template which already created an tested and works fine, but i have two problems when i tried to do it in C# code (in a mvc3 project).

1. Which are the differences between EnvDTE80, EnvDTE90 and EnvDTE100 because i tried to do this example with EnvDTE100 but it doesn't work because the object handle it's Solution4 not Solution2 and Solution4 doesn't have the same behavior.
2. How can I create the project without use the default path, but an specific folder that i need

UPDATE

here's the code that works if I used the dll called EnvDTE80

  System.Type type = System.Type.GetTypeFromProgID("VisualStudio.DTE.8.0");
  Object obj = System.Activator.CreateInstance(type, true);
  EnvDTE80.DTE2 dte = (EnvDTE80.DTE2)obj;
  Solution2 _solution = (Solution2)dte.Solution;
  string projectTemplatePath = @"C:\Documents and Settings\jmachado\Escritorio";
  projectTemplatePath =_solution.GetProjectTemplate("",""); <-- looking for some overload to create project based in a specific folder an not from '<drive>:\Program Files\Microsoft Visual Studio 8\Common7\IDE\ProjectTemplates\Language.'

But if i used the EnvDTE100

  System.Type type = System.Type.GetTypeFromProgID("VisualStudio.DTE.10.0");
  Object obj = System.Activator.CreateInstance(type, true);
  EnvDTE100.DTE2 dte = (EnvDTE100.DTE2)obj;
  Solution4 _solution = (Solution4)dte.Solution;
  string projectTemplatePath = @"C:\Documents and Settings\jmachado\Escritorio";
  projectTemplatePath =_solution.GetProjectTemplate("",""); <-- looking for some overload to create project based in a specific folder an not from '<drive>:\Program Files\Microsoft Visual Studio 8\Common7\IDE\ProjectTemplates\Language.'

and Say's that DTE2 doesn't exit's in the namespace of EnvDTE100

Answer 1

EnvDTE80, EnvDTE90 and EnvDTE100 are DTE type libraries for VS 8.0 (2005), 9.0 (2008) and 10.0 (2010), correspondingly.

There are only two DTE root object interfaces, as of VS2010 - DTE2 being the latest. So, to get the DTE object for VS 2010, you do:

System.Type type = System.Type.GetTypeFromProgID("VisualStudio.DTE.10.0");
Object obj = System.Activator.CreateInstance(type, true);
EnvDTE80.DTE2 dte = (EnvDTE100.DTE2)obj;

Note that ProgID is for "10.0", but variable type is still EnvDTE80.DTE2.

The rest should work from there. Note also that you can always cast Solution4 to Solution2 if you need it (but GetProjectTemplate should be available directly on Solution4).