Capitalizing words in a string using c#

Question

I need to take a string, and capitalize words in it. Certain words (\"in\", \"at\", etc.), are not capitalized and are changed to lower case if encountered. The first word s

Answer 1

A slight improvement on jonnii's answer:

var result = Regex.Replace(s.Trim(), @"\b(\w)", m => m.Value.ToUpper());
        result = Regex.Replace(result, @"\s(of|in|by|and)\s", m => m.Value.ToLower(), RegexOptions.IgnoreCase);
        result = result.Replace("'S", "'s");