Custom message not working for C++ Project template with Wizard

I have followed the tutorial here http://msdn.microsoft.com/en-us/library/ms185301.aspx to produce a template project that lets me substitute parameters in my code using a wizard.

This works for all my C# projects for example if I have the following in my template:

using System.Runtime.Serialization;
using $customvariable$Definitions;

namespace $customvariable$Objects
{
    /// <summary>
    /// $customvariable$ Camera
    /// </summary>
    public class $customvariable$Camera
    {
        #region Constructor
        /// <summary>
        /// Instantiates a new instance of the $customvariable$Camera class
        /// </summary>
        public $customvariable$Camera() :
            base()
        {

        }
        #endregion
    }

I can rename my customvariable to anything I want and it gets generated in the resulting project.

BUT If I do the exact same in a visual C++ project the custom variables do not get replaced.

How can I get this to work for C++ code files as well? Does something have to be done differently for C++ code files??