Как я могу использовать htaccess для принуждения www. на нескольких доменах

        var content = "zf3kabxcde224lkzf3mabxc51+crsdtzf3nab=";
        var patternLength = 3;            
        var patterns = new HashSet<string>();

        for (int i = 0; i < content.Length - patternLength + 1; i++)
        {
            var pattern = content.Substring(i, patternLength);                
            var Occurrence = Regex.Matches(content, pattern.Replace("+", @"\+")).Count;
            if (Occurrence > 1 && !patterns.Contains(pattern))
            {
                Console.WriteLine(pattern + " : " + Occurrence);
                patterns.Add(pattern);
            }
        }