file.cs

public class EmailAddress
    {
        [Match("^")] public string _;
        [Match(@"\w+")] public string User;
        [Match("@")] public string _1;
        [Match("[^@]+")] public string Host;
        [Match("$")] public string _2;
    }

    public static class Matcher
    {
        public static T Match<T>(string input) where T: new()
        {
            var props = typeof (T).GetFields()
                .Select(x => new {
                    Attr = x.GetCustomAttributes(typeof (MatchAttribute), false).Cast<MatchAttribute>().First(),
                    Prop = x
                }).OrderBy(x => x.Attr.Order);
            var re = string.Join("", 
                props.Select(x => new {x.Attr.Pattern, x.Prop.Name}).
                Select(x => x.Name.StartsWith("_") ? (x.Pattern) : $"({x.Pattern})"));
            var match = Regex.Match(input, re);
            var res = new T();
            var toFill = props.Where(x => !x.Prop.Name.StartsWith("_")).ToList();
            for(var i = 0; i < toFill.Count(); i++)
            {
                toFill[i].Prop.SetValue(res, match.Groups[i].Value);
            }
            
            return res;
        }
    }
    [AttributeUsage(AttributeTargets.Field)]
    public sealed class MatchAttribute : Attribute
    {
        public MatchAttribute(string pattern, [CallerLineNumber] int order = 0)
        {
            Order = order;
            Pattern = pattern;
        }
        public string Pattern { get;  }
        public int Order { get; }
    }

    class Program
    {
        
        static void Main(string[] args)
        {
            var addr = Matcher.Match<EmailAddress>("[email protected]");
           
            Console.WriteLine("Done");
        }
    }