FanPanel Item Order

I'm using a FanPanel as an ItemTemplate in a ListBox. I'd like to reverse the order in which the items appear. Currently, they appear in this order, numbered as defined in the ListBox:

4    3    2    1

And I'd like them to appear:

1    2    3    4

Is there any way to reverse the order? If I reverse the order, inactive items should appear on the right of the screen. I can manually reverse the listbox items and then set the selectedindex to the last item to achieve the results but the scrollbar then works in the opposite direction that it should.

<ListBox
        Background="Transparent"
        BorderThickness="0"
        ClipToBounds="False"
        Grid.Row="1"
        Margin="0,10,0,0"
        PreviewMouseWheel="ListBox_PreviewMouseWheel"
        ScrollViewer.HorizontalScrollBarVisibility="Visible"
        ScrollViewer.VerticalScrollBarVisibility="Disabled">
        <ListBox.ItemsPanel>
          <ItemsPanelTemplate>
            <views:FanPanel
              BackAngleStep="0"
              BackOffsetStep="700, 0"
              BackOpacityStep="0.8"
              ForeAngleStep="0"
              ForeOffsetStep="700, 0"
              ForeOpacityStep="0.8"
              ForeElementLayoutPlacement="Below" />
          </ItemsPanelTemplate>
        </ListBox.ItemsPanel>
        <ListBox.Items>
          <ListBoxItem>
            ...
          </ListBoxItem>
        </ListBox.Items>
      </ListBox>

 Thank you!