Dependency Property binding in a custom control

I need help binding to custom control specified in DataTemplate which is part of a custom control based on ItemsControl.  The xaml for the custom control looks like:
<Style x:Key="{x:Type local:MyItemPanel}" TargetType="{x:Type local:MyItemPanel}">
 <Setter Property="Template">
  <Setter.Value>
   <ControlTemplate TargetType="{x:Type ItemsControl}" >
    <ItemsControl x:Name="PART_itmCtrl" ItemsSource="{TemplateBinding ItemsSource}">
     <ItemsControl.ItemsPanel>
      <ItemsPanelTemplate>
       <WrapPanel x:Name="PART_wrapPanel" />
      </ItemsPanelTemplate>
     </ItemsControl.ItemsPanel>
     <ItemsControl.ItemTemplate>
      <DataTemplate >
       <local:MyInnerCustomTextBoxControl Text="{Binding Path=TokenValue}" WaterMark="{Binding Path=Token}"
         BorderBrush="{TemplateBinding local:MyItemPanel.WMBorderBrush}"
         HorizontalAlignment="Left" BorderThickness="1" />
      </DataTemplate>
     </ItemsControl.ItemTemplate>
    </ItemsControl>
   </ControlTemplate>
  </Setter.Value>
 </Setter>
</Style>

<Style x:Key="{x:Type local:MyItemPanel}" TargetType="{x:Type local:MyItemPanel}"><Setter Property="Template"><Setter.Value><ControlTemplate TargetType="{x:Type ItemsControl}" ><ItemsControl x:Name="PART_itmCtrl" ItemsSource="{TemplateBinding ItemsSource}"><ItemsControl.ItemsPanel><ItemsPanelTemplate><WrapPanel x:Name="PART_wrapPanel" /></ItemsPanelTemplate></ItemsControl.ItemsPanel><ItemsControl.ItemTemplate><DataTemplate ><local:MyInnerCustomTextBoxControl Text="{Binding Path=TokenValue}" WaterMark="{Binding Path=Token}" 
									BorderBrush="{TemplateBinding local:MyItemPanel.WMBorderBrush}"
									HorizontalAlignment="Left" BorderThickness="1" /></DataTemplate></ItemsControl.ItemTemplate></ItemsControl></ControlTemplate></Setter.Value></Setter></Style>

The custom control is used in xaml as follow:

<y:MyItemPanel x:Name="TokenIP" WMBorderBrush="Crimson"  />

I am trying to pass it into the DataTemplate.  The problem is that the DataTemplate binds to the the collection defined in the View Model, which works above in the Text="{Binding Path=TokeValue}" but doesn't appear to work in the BorderBrush="{TemplateBinding local:MyItemPanel.WMBorderBrush}", so I'm thinking that my xaml syntax is not correct.

I'm looking for the proper syntax that binds BorderBrush to the WMBorderBrush dependency property of MyItemPanel.

Thanks

Robotuner