using System;

using System.Collections.Generic;

using System.Linq;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        var list = new List<string>();

        list.Add("665057 BC LTD / KX WHEELS -- 5380239 -- ");       

        list.Add("ABRAHAM CHEVROLET MIAMI INC -- 6574754 -- ");

        list.Add("AC COLLINS FORD -- 418426 -- ");

        list.Add("ACCESS FORD LTD -- 2322732 -- ");

        list.Add("ACCESSOR-EASE -- 5809346 --");

​

        string pattern = "(.*)(-- )(.*)( --)";

        Regex r1 = new Regex(pattern);

​

        foreach (string s in list)

        {

            Match match = r1.Match(s);

            if (match.Success)

            {

                string v = match.Groups[3].Value;

                Console.WriteLine("Number: {0}", v);

            }

        }

    }

}