how to get date from week number of month and week day?

using System;

public class Program
{
	public static void Main()
	{
		DateTime dt = new DateTime(2016, 2, 1); // create the start date of the month and year
		DayOfWeek firstDayOfWeekofMonth = dt.DayOfWeek; // Find out the day of week for that date
		int myWeekNumInMonth = 4; // You want the 4th week, this may cross over to the following month!
		string myDayOfWeek = "Wednesday";  // You want Wednesday
		int myDayOfWeekInt = day2Int(myDayOfWeek);
		int diff = myDayOfWeekInt - (int)firstDayOfWeekofMonth;
		Console.WriteLine("The answer is {0:d}.", dt.AddDays(7 * (myWeekNumInMonth - 1) + diff));
	}

	public static int day2Int(string dayOfWeek)
	{
		switch (dayOfWeek)
		{
			case "Sunday":
				return 0;
			case "Monday":
				return 1;
			case "Tuesday":
				return 2;
			case "Wednesday":
				return 3;
			// Finish the rest yourself
			default:
				return -1; // Do error checking
		}
	}
}