using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string preferedName = "Empty (5) Preset";

        int index = 1;

        Match match = Pattern.Match(preferedName);

​

        if (match.Success)

        {

            index = Int32.Parse(match.Groups[2].Value) + 1;

            preferedName = match.Groups[1].Value + "({0})" + match.Groups[3].Value;

        }

        else

            preferedName += " ({0})";

        Console.WriteLine(preferedName);

        Console.WriteLine(index);

    }

    private static readonly Regex Pattern = new Regex(@"(.*)\((\d+)\)(.*)", RegexOptions.Compiled);

}