How to change the size of a chart marker?

Hi,

I'm developing an XYChart with a LineSeries. What I would like to do is when the series reaches the Maximum XAxis value and the chart refreshes, the series will start again on leftmost part of the chart and the line series will have a vertical line in front of it. Upon evaluating available controls of Actipro, I saw that this would be achievable by using the chart marker and setting the chart marker visibility to "last", only I need the marker to be a vertical line. Is this possible? I tried creating a template for the line but the size of the marker seems to be restricted somewhere I can not find.

<charts:LineSeries.MarkerStyle>
<Style TargetType="charts:ChartMarker">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="charts:ChartMarker">
<Rectangle
x:Name="LineMarker"
Fill="{TemplateBinding Background}"
Height="50" />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</charts:LineSeries.MarkerStyle>

Any help would be very appreciated. Thanks!!