Binding to the Mask Property in DataGridMaskedTextColumn

I've got a newbie question about binding to the Mask property (pretty slick feature BTW...)

Is it possible to bind the Mask property to a Property in my Data Model?

I would like to be able to change the regex mask dynamically when another property changes. I've embedded the RegEx's into the Mask Property in XAML so I know they work.

When I have the Mask Property Bound to a Property in my Model it no longer works and generates the following exception:

System.Windows.Data Error: 2 : Cannot find governing FrameworkElement or FrameworkContentElement for target element. BindingExpression:Path=IdRegEx; DataItem=null; target element is 'DataGridMaskedTextColumn' (HashCode=26966483); target property is 'Mask' (type 'String')


It seems to indicate that there isn't a Visual or Logical Parent. Am I not understanding how to bind to the Mask Property?



The ThemedDataGrid Xaml is as follows:

<datagrid:ThemedDataGrid Name="ActiProDataGrid"
AutoGenerateColumns="False" GridLinesVisibility="All"
IsReadOnly="False"
SelectionMode="Single" SelectionUnit="FullRow"
ItemsSource="{Binding List}"
SelectedIndex="{Binding SelIndex, Mode=TwoWay}"
MaxHeight="300"
IsSynchronizedWithCurrentItem="True">
<datagrid:ThemedDataGrid.Columns>
<datagrideditors:DataGridMaskedTextColumn Header="ID(Masked)" Mask="{Binding IdRegEx, UpdateSourceTrigger=PropertyChanged}"
Width="Auto" HeaderStyle="{StaticResource CenterAlignedColumnHeaderStyle}"
EditingElementStyle="{StaticResource CenterCellStyle}"
Binding="{Binding Id,
ValidatesOnDataErrors=True, UpdateSourceTrigger=PropertyChanged, NotifyOnValidationError=True}">
</datagrideditors:DataGridMaskedTextColumn>
<datagrideditors:DataGridInt32Column Header="Type"
Width="Auto"
Binding="{Binding Type}">
</datagrideditors:DataGridInt32Column>
</datagrid:ThemedDataGrid.Columns>
</datagrid:ThemedDataGrid>


public class People : INotifyPropertyChanged, IDataErrorInfo
{
...

public People(string Name, string Id)
{
Name_ = Name;
Id_ = Id;
IdRegEx = (type_ == 0) ? "[0-9A-F]{32}" : "[0-9A-F]{8}";
}

...

public int Type
{
get { return type_; }
set
{
type_ = value;
IdRegEx = (type_ == 0) ? "[0-9A-F]{32}" : "[0-9A-F]{8}";
NotifyPropertyChanged("Type");
NotifyPropertyChanged("IdRegEx");
}
}

...


public partial class Window1 : Window, INotifyPropertyChanged
{
private ObservableCollection<People> list_;

public ObservableCollection<People> List
{
get {return list_;}
set { list_ = value; NotifyPropertyChanged("List"); }
}

...
}