smartphone output reversal (password generator)

Question

Hi,first of all thank you in advanced for any help with this one, ive only been using c# for a few weeks.  Im using a smartphone device to take an input from a user for a maximum of 5 charcater (example), replace numbers with * and output the password in reverse order, here is what i have thus far:

using System;
using System.Linq;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace Exercise_6
{
public partial class Form1 : Form
{

public Form1()
{
InitializeComponent();
}
private void menuItem1_Click(object sender, EventArgs e)
{

string password = txtInputPass.Text;
password = password.Replace("A", "X");
password = password.Replace("E", "X");
password = password.Replace("I", "X");
password = password.Replace("O", "X");
password = password.Replace("U", "X");
password = password.Replace("a", "X");
password = password.Replace("e", "X");
password = password.Replace("i", "X");
password = password.Replace("o", "X");
password = password.Replace("u", "X");
password = password.Replace("0", "Z");
password = password.Replace("1", "Z");
password = password.Replace("2", "Z");
password = password.Replace("3", "Z");
password = password.Replace("4", "Z");
password = password.Replace("5", "Z");
password = password.Replace("6", "Z");
password = password.Replace("7", "Z");
password = password.Replace("8", "Z");
password = password.Replace("9", "Z");
txtGenPass.Text = password;

}
}
} 

 

 
after searching through the web i cant seem to find/figure the best way to change the above??