This is a little complex, because you want to find the highest numeric value of a group of string based numbers
stanly1.doc
stanly2.doc
stanly10.doc
And the string comparison will say that stanly2.doc has the highest value. You can do it with a little judicial application of LINQ methods and a regex to extract the number:
string[] files = Directory.GetFiles(@"D:\Temp", "stanly*.doc", SearchOption.AllDirectories);
Regex number = new Regex(@"(?<=.*?)\d+(?=\.doc$)");
var highest = files.OrderByDescending(f => int.Parse(number.Match(f).Value)).First();
Console.WriteLine(highest);