Private Sub TextBox1_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
On Error GoTo Err
 
    If IsNumeric(Chr(KeyAscii)) = True Or Chr(KeyAscii) = "," Then
    Else
        KeyAscii = 0
    End If
 
Exit Sub
Err: KeyAscii = 0
End Sub

Mit freundlichen Gr??en,
Andy G.