Prueba lo siguiente para el textbox "Uno"
Private Sub SpinButton1_SpinDown()
Dim t As String
t = "Uno"
Uno.BackColor = &HFFFFFF
Dos.BackColor = &HFFFFFF
Tres.BackColor = &HFFFFFF
Cuatro.BackColor = &HFFFFFF
If Controls(t) = "" Then
Controls(t) = 9
Else
If Val(Controls(t)) - 1 < 0 Then
Controls(t) = ""
Else
Controls(t) = Val(Controls(t)) - 1
End If
End If
End Sub
'
Private Sub SpinButton1_SpinUp()
Dim t As String
t = "Uno"
Uno.BackColor = &HFFFFFF
Dos.BackColor = &HFFFFFF
Tres.BackColor = &HFFFFFF
Cuatro.BackColor = &HFFFFFF
If Controls(t) = "" Then
Controls(t) = 0
Else
If Val(Controls(t)) + 1 > 9 Then
Controls(t) = ""
Else
Controls(t) = Val(Controls(t)) + 1
End If
End If
End Sub