Multi-layer style in Silverlight ressource

Question

I wish to set a property the C# property of a Chart object :

Chart.DefaultView.ChartArea.AxisX.DefaultLabelFormat ="dd mm aa";

but I will to do this with the styles in Silverlight :

<Application.Resources>
        <Style x:Key="myStyle" TargetType="telerikCharting:RadChart"> ...

but I cannot make a :

<Setter Property="DefaultView.ChartArea.AxisX.DefaultLabelFormat" Value="dd.MM.yy hh:mm:ss">

It doesn't work.

Anyone have an idea ?

Thanks in advance.

Narglix