WinMerge in MKS Diff and Merge Tools

I've done this integration a number of times and I've always had to resort to creating a C# program to discover what the options really are:

    class Program
    {
        static void Main(string[] args)
        {
            for (int i = 0; i < args.Length; i++)
            {
                Console.WriteLine("[" + i + "]: " + args[i]);
            }
            Console.Read();
        }
    }

then I hook it up to the dialog and do a diff.

Here's the current options that I've put in:

C:\Program Files\WinMerge\WinMergeU.exe /maximize /e /x /ul /ur 
                  /dl "{1}" /dr "{2}" "{3}" "{4}"