using System; using System.Text.RegularExpressions; public class Test { public static void Main() { string pattern = @"^(?=.*\d)(?=.*[!@#$&()`.+,\/\-])(?=.*[a-zA-Z])[a-zA-Z\d!@#$&()`.+,\/-]+$"; string input = @"HOAUD039# HOAUD091 HOAUD00$"; RegexOptions options = RegexOptions.Multiline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine(m.Value); } } }