I'm writing a little extension for Visual Studio 2015. I added a VSPackage to to embed some CustomCommands on the Shortcut Menu you get when you RightClick on a Project or a Folder inside the Solution Explorer.
What I would like to do now is "open the Add New Item dialog and select the one of the templates I've installed with this VSPackage".
This is the Code I use to initialize my commands:
private TemplateCommand(Package package)
{
    if (package == null)
        throw new ArgumentNullException(nameof(package));
    _package = package;
    var commandService = ServiceProvider.GetService(typeof(IMenuCommandService)) as OleMenuCommandService;
    if (commandService == null)
        return;
    AddCommand(commandService, CommandId, CreateCustomTemplate);
}
The CreateCustomTemplate callback code is this:(for the moment I simply create a messageBox, just to ensure it works)
private void CreateCustomTemplate(object sender, EventArgs eventArgs)
{
    //TODO: code to replace!
    var message = string.Format(CultureInfo.CurrentCulture, "Inside {0}.CreateCustomTemplate()", GetType().FullName);
    // Show a message box to prove we were here
    VsShellUtilities.ShowMessageBox(
        ServiceProvider,
        message,
        "CREATE CustomTemplate",
        OLEMSGICON.OLEMSGICON_INFO,
        OLEMSGBUTTON.OLEMSGBUTTON_OK,
        OLEMSGDEFBUTTON.OLEMSGDEFBUTTON_FIRST);
}
So, to recap, how do I open the Add New Item dialog box and select a specific item template?
As an example, when you try to create a Class or a UserControl right-clicking on a folder in the solution explorer

You obtain something similar to this:

And this is, exactly, what I'm trying to achieve. Obviously I would like to create my own template and not the UserControl.
If you need any clarification feel free to ask. Thank you in advance for any suggestion