How to separate event code behind to seperate class?

So far i separated action with Command Binding. but i need to implent many thing to work same as built-in event. ex, OnClick, OnChange and so on. the MVVM pattern only means is no code behind in ViewModel class. all thing like Component. instead make all thing from scratch. why not just make Event in ViewModel implementation like component. so just attacch and detach that event collection class. is there new way to do this? so far i can think is encapsulate control with event and inhrited to viewmodel class.

public class Utility
{
 public static string Manipulation(string search)
 {
   return search + "Reesult";
 }
}

public class CustomWindow : Window
{
  protected virtual void SearchBtn(object sender, RoutedEventArgs e)
  {
    MessageBox.Show( Utility.Manipulation(search.Text) );
  }
}

public partial WindowViewModel : CustomWindow
{
    public WindowViewModel
    {
        InitializeComponent();
    }
}

<TextBox x:Name="search" />
<Button Click="SearchBtn"> Search </Button>