Accessing Telerik Silverlight RadGridView from Button on Group header

[Rick]

I have a RadGridView, that groups its contents.
I have a Button on the group header
When I click on the button (btnSave) I would like to get access to the group to read the group key.
What can I put in the Click of btnSave to accomplish this?

<telerik:RadGridView x:Name="grdNotams" Grid.Row="1"
AutoGenerateColumns="False" RowIndicatorVisibility="Collapsed"
ShowGroupPanel="False"><BR> <telerik:RadGridView.Columns><BR>  <telerik:GridViewDataColumn
UniqueName="colNewStatus" DataMemberBinding="{Binding NewStatus}" Header="New
Status" IsFilterable="False"
IsSortable="False"><BR>   <telerik:GridViewDataColumn.CellTemplate><BR>    <DataTemplate><BR>     <StackPanel
Orientation="Horizontal"><BR>      <telerik:RadRadioButton
Content="C" Width="30" IsChecked="{Binding NewStatus, Mode=TwoWay,
Converter={StaticResource StringToBooleanConverter},ConverterParameter=C}"
GroupName="{Binding
RadioButtonName}"/><BR>      <telerik:RadRadioButton
Content="M" Width="30" Margin="5,0,0,0"  IsChecked="{Binding NewStatus,
Mode=TwoWay, Converter={StaticResource
StringToBooleanConverter},ConverterParameter=M}" GroupName="{Binding
RadioButtonName}"/><BR>      <telerik:RadRadioButton
Content="I" Width="30" Margin="5,0,0,0"  IsChecked="{Binding NewStatus,
Mode=TwoWay, Converter={StaticResource
StringToBooleanConverter},ConverterParameter=I}" GroupName="{Binding
RadioButtonName}"/>
<BR>     </StackPanel><BR>    </DataTemplate><BR>   </telerik:GridViewDataColumn.CellTemplate><BR>  </telerik:GridViewDataColumn><BR>  <telerik:GridViewDataColumn
Header="Status" UniqueName="colStatus" DataMemberBinding="{Binding Model.Status,
Converter={StaticResource StatusConverter}}" HeaderTextAlignment="Center"
TextAlignment="Center" IsFilterable="False"
IsSortable="False"/><BR>  <telerik:GridViewDataColumn
Header="Trip #" UniqueName="colTripNumber" DataMemberBinding="{Binding
Model.TripNumber}" HeaderTextAlignment="Center" TextAlignment="Center"
IsFilterable="False"
IsSortable="False"/><BR>  <telerik:GridViewDataColumn
Header="Date" UniqueName="colDate" DataMemberBinding="{Binding
Model.DepartureTime}" DataFormatString="d"  HeaderTextAlignment="Center"
TextAlignment="Center" IsFilterable="False"
IsSortable="False"/><BR> </telerik:RadGridView.Columns><BR> <telerik:RadGridView.GroupHeaderTemplate><BR>  <DataTemplate><BR>   <StackPanel
Orientation="Horizontal"><BR>    <telerik:RadButton
x:Name="btnSave"
Click="btnSave_Click"><BR>     <StackPanel
Orientation="Vertical"><BR>      <Image
Source="../images/save.jpg" Height="30" Width="30"
HorizontalAlignment="Center"/><BR>      <TextBlock
TextAlignment="Center"
TextWrapping="Wrap">Update</TextBlock><BR>     </StackPanel><BR>    </telerik:RadButton><BR>    <TextBlock
Text="{Binding Group.Key}" FontSize="14" FontWeight="Bold" FontStyle="{Binding
EarliestNotamDepartureTime, Converter={StaticResource
DateTimeToItalicsConverter}}" TextWrapping="Wrap" VerticalAlignment="Center"
Padding="5"/><BR>   </StackPanel><BR>  </DataTemplate><BR> </telerik:RadGridView.GroupHeaderTemplate><BR> <telerik:RadGridView.GroupDescriptors><BR>  <telerik:GroupDescriptor
Member="NotamGroup"
><BR>  </telerik:GroupDescriptor><BR>  <telerik:GroupDescriptor
Member="Model.NotamText"><BR>  </telerik:GroupDescriptor><BR> </telerik:RadGridView.GroupDescriptors><BR></telerik:RadGridView><BR>