How can I best handle WPF radio buttons?

I've got some RadioButtons in my XAML...

<StackPanel>
    <RadioButton Name="RadioButton1" GroupName="Buttons" Click="ButtonsChecked" IsChecked="True">One</RadioButton>
    <RadioButton Name="RadioButton2" GroupName="Buttons" Click="ButtonsChecked">Two</RadioButton>
    <RadioButton Name="RadioButton3" GroupName="Buttons" Click="ButtonsChecked">Three</RadioButton>
</StackPanel>

And I can handle their click events in the Visual Basic code. This works...

    Private Sub ButtonsChecked(ByVal sender As System.Object, _
                               ByVal e As System.Windows.RoutedEventArgs)
        Select Case CType(sender, RadioButton).Name
            Case "RadioButton1"
                'Do something one
                Exit Select
            Case "RadioButton2"
                'Do something two
                Exit Select
            Case "RadioButton3"
                'Do something three
                Exit Select
        End Select
    End Sub

But, I'd like to improve it. This code fails...

<StackPanel>
    <RadioButton Name="RadioButton1" GroupName="Buttons" Click="ButtonsChecked" Command="one" IsChecked="True">One</RadioButton>
    <RadioButton Name="RadioButton2" GroupName="Buttons" Click="ButtonsChecked" Command="two">Two</RadioButton>
    <RadioButton Name="RadioButton3" GroupName="Buttons" Click="ButtonsChecked" Command="three">Three</RadioButton>
</StackPanel>

    Private Sub ButtonsChecked(ByVal sender As System.Object, _
                               ByVal e As System.Windows.RoutedEventArgs)
        Select Case CType(sender, RadioButton).Command
            Case "one"
                'Do something one
                Exit Select
            Case "two"
                'Do something two
                Exit Select
            Case "three"
                'Do some