How to format the display text as currency in WinRT NumericUpDown?

<Page
x:Class="App4.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:App4"
xmlns:navigation="using:Syncfusion.UI.Xaml.Controls.Navigation"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:syncfusion="using:Syncfusion.UI.Xaml.Controls.Input"
xmlns:Media="using:Syncfusion.UI.Xaml.Controls.Media"
xmlns:input="using:Syncfusion.UI.Xaml.Controls.Input"
xmlns:converters="using:Syncfusion.UI.Xaml.Converters"
mc:Ignorable="d">
<Page.Resources>
<converters:ColorToBrushConverter x:Key="brushconverter1"/>
</Page.Resources>
<Grid x:Name="Grid1" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<input:SfNumericUpDown x:Name="numericUpDown" HorizontalAlignment="Center" VerticalAlignment="Center" Width="200" FormatString="C" Value="123.45"/>
</Grid>
</Page>

using Syncfusion.UI.Xaml.Controls.Input;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238
namespace App4
{
/// <summary>
/// An empty page that can be used on its own or navigated to within a Frame.
/// </summary>
public sealed partial class MainPage : Page
{
public MainPage()
{
this.InitializeComponent();
SfNumericUpDown numericupdown = new SfNumericUpDown();
numericupdown.Width = 200;
numericupdown.HorizontalAlignment = HorizontalAlignment.Center;
numericupdown.VerticalAlignment = VerticalAlignment.Center;
numericupdown.FormatString = "C";
numericupdown.Value = 123.45;
Grid1.Children.Add(numericupdown);
}
}
}