ExtractStrings.cs

static string Between(this string source, string left, string right)
    {
        return Regex.Match(
                source,
                string.Format("{0}(.*){1}", left, right))
            .Groups[1].Value;
    }


private static List<string> ExtractFromString(string source, string start, string end)
    {
        var results = new List<string>();

        string pattern = string.Format(
            "{0}({1}){2}", 
            Regex.Escape(start), 
            ".+?", 
             Regex.Escape(end));

        foreach (Match m in Regex.Matches(source, pattern))
        {
            results.Add(m.Groups[1].Value);
        }

        return results;
    }
    
    
    public static class StringExtensionMethods
    {
    public static List<string> EverythingBetween(this string source, string start, string end)
    {
        var results = new List<string>();

        string pattern = string.Format(
            "{0}({1}){2}",
            Regex.Escape(start),
            ".+?",
             Regex.Escape(end));

        foreach (Match m in Regex.Matches(source, pattern))
        {
            results.Add(m.Groups[1].Value);
        }

        return results;
    }
}