create progressive serie

[andr_01]

file:///C:/DOCUME%7E1/9335%7E1/LOCALS%7E1/Temp/moz-screenshot.pngHello,http://img707.imageshack.us/i/24141096.png/

I have the bar chart and ItemsSource which I bind to the bar chart

Item structure looks like this
class Item
{
public double Value1 {get; set;}
public double Value2 {get; set;}
...
public double Value3 {get; set;}
}

Thus, I have N series. Each of them must have the value from 0 to 1.0
I use percentage for AxisY so I need to show values from 0% to 100%

But for some series I need to show a http://img707.imageshack.us/i/24141096.png/opaque background bar with the value 100% (in order to show relative progress). For the particular series only!
<a href="http://img707.imageshack.us/i/24141096.png/" target="_blank"></a>

How can I implement it? I can't use Bar.Overlap property because in this case background overlaps all series. I can't use separate series for all background bars because I don't have appropriate properties in my data source. Even if I had these properties I would have needed to use Serie.Stacked property for the background bars. But in this case the tooltip shows unnecessary property name and total height of two bars is more then 100%.

 Could you help me, please?