I don't know what code you have but here is a trick..
in order to have different random number all you have to do is to put the code Randomize in the main form where the random number is generated. But the problems may occurs here, it is not a major but rather a logical problem.
For Each ctrl As Control In Me.Controls("pnlMainPanel").Controls
If ctrl.GetType Is GetType(System.Windows.Forms.Panel) Then
For Each subCtrl As Control In ctrl.Controls
If subCtrl.GetType Is GetType(System.Windows.Forms.TextBox) Then
If subCtrl.GetType Is ...