using System;
using System.Text.RegularExpressions;
public class Test
{
public static void Main()
{
string stroka = "На путях я вижу сорок резво скачущих сорок.";
string needle = "сорок";
Regex ragularka = new Regex(needle + @"(\w*)");
MatchCollection matches = ragularka.Matches(stroka);
foreach (Match match in matches)
{
Console.WriteLine(match.Value);
}
}
}