Modify KeyPress Event For Multiple Objects

There are two ways to do that. One is to create a KeyPress event procedure and list all the associated textboxes in the procedure's Handles clause:

Private Sub TextBox_KeyPress(ByVal sender As Object, _
ByVal e As System.Windows.Forms.KeyPressEventArgs) _
Handles TextBox1.KeyPress, TextBox2.KeyPress, TextBox3.KeyPress ' ...etc.

End Sub

The other is to create your own control which Inherits from TextBox and which overrides the OnKeyPress event:

Public Class MyTextBox
Inherits System.Windows.Forms.TextBox

Protected Overrides Sub OnKeyPress(ByVal e As System.Windows.Forms.KeyPressEventArgs)
MyBase.OnKeyPress(e)
' Your validation code here
End Sub

End Class

Then instead of placing standard a TextBox on your form, use your new MyTextBox class.

You should be aware that KeyPress validation does not prevent the user from pasting invalid text from the clipboard. You're better off using the TextChanging or Validating events.