string basePath = "C:\\Users\\username\\Desktop\\"; string fileName = Path.GetFileNameWithoutExtension("example.txt"); string fullNewPath = Path.Add(basePath, fileName + "_backup.txt"); Console.WriteLine(fullNewPath);In this example, we set up a base path for our files, and then use the GetFileNameWithoutExtension method to get the file name without the extension from the original file name. We then use the Add method to add "_backup.txt" to the end of the file name and create a new path. Finally, we print out the new path to the console. This code depends on the System.IO namespace, which is part of the .NET Framework.