gripe.cs

public static class Extensions
{
    public enum Variables
    {
        CLASS_ATTR,
        FINISH
    }

    public static string GetReportProperty(this TSM.Part part, Variables variable)
    {
        string value = "";
        part.GetReportProperty(variable.ToString(), ref value);
        return value;
    }
}

// usage...
private void demo()
{
    ModelObjectEnumerator modelObjectEnum = modelObjectSelector.GetSelectedObjects();
    while (modelObjectEnum.MoveNext())
    {
        if (modelObjectEnum.Current is TSM.Part)
        {
            TSM.Part part = (TSM.Part)modelObjectEnum.Current;
            Console.WriteLine(part.GetReportProperty(Extensions.Variables.CLASS_ATTR));
        }
    }
}