UserControl with Exposable Command on WPF - wpf

Question

I'm creating a Toolbar with some buttons, and I want each button to execute an different command according to the ViewModel attached to it's DataContext, so I created if like this:
public readonly DependencyProperty NewCommandProperty = DependencyProperty.Register(
"NewCommand", typeof(ICommand),
typeof(VirtueGridToolbar));
public ICommand NewCommand
{
get
{
return (ICommand)GetValue(NewCommandProperty);
}
set
{
SetValue(NewCommandProperty, value);
}
}
public GridToolbar()
{
InitializeComponent();
}
and the xaml of the control is this:
<UserControl x:Class="Virtue.Modules.Library.Controls.GridToolbar"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ToolBar Background="Transparent">
<ToolBar.Items>
<Button x:Name="NewButton"
Width="25"
Height="25"
ToolTip="Novo"
Command="{Binding NewCommand}">
<Image Source="{DynamicResource NewLarge}" />
</Button>
<Button x:Name="EditButton"
Width="25"
Height="25"
ToolTip="Editar">
<Image Source="{DynamicResource EditLarge}" />
</Button>
<Button x:Name="DeleteButton"
Width="25"
Height="25"
ToolTip="Excluir">
<Image Source="{DynamicResource DeleteLarge}" />
</Button>
<Separator />
<Button x:Name="SaveButton"
Width="25"
Height="25"
ToolTip="Excluir">
<Image Source="{DynamicResource SaveLarge}" />
</Button>
</ToolBar.Items>
</ToolBar>
</UserControl>
But when I add the UserControl to another control and attribute the Command
<V:GridToolbar NewCommand="{Binding Path=New}" />
the command does not execute.
Any suggestions?
Tks,
Diego