True, if youre going as far as adding an event to all textboxs in a control and have to condition unwanted textboxs youre better off making a custom contol

Code:
    Private Class tb
        Inherits TextBox
        Dim AllowKeys() As Char = {
                    "1"c, "2"c, "3"c, "4", "5"c, "6"c, "7"c, "8"c, "9"c, "0"c}
        Private Sub TextBox1_KeyPress(sender As Object, e As KeyPressEventArgs) Handles Me.KeyPress

            If Not AllowKeys.Contains(e.KeyChar) Then

                e.Handled = True
            End If
        End Sub

    End Class
and create them
Code:
        Dim FLPTxtBoxGroup As New FlowLayoutPanel With {
            .FlowDirection = FlowDirection.LeftToRight,
            .Dock = DockStyle.Fill,
            .AutoScroll = True}
        Controls.Add(FLPTxtBoxGroup)
        For i As Integer = 0 To 140
            Dim WonkyNumericalTextBox As New tb With {
                .Name = "WonkyTextBox" & i.ToString}

            FLPTxtBoxGroup.Controls.Add(WonkyNumericalTextBox)
        Next