How add comma to StringFormat in XAML

Hi, i have this code in XAML

<DataGridTextColumn Header="Cena" Width="auto"  Binding="{Binding Path=Price,StringFormat='###,###.##&#x002C;-'}"/>

I need show numbers in this format 456,896,- but i do not know how insert a comma after the number. 

Thank youfor any advice. :-)