MainWindow.xaml

<Window x:Class="ClipboardRegex.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Enter Regex to apply to clipboard copies here" Height="140" Width="525">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition/>
            <RowDefinition/>
        </Grid.RowDefinitions>

        <TextBox x:Name="FindWhat" Text="Find What" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" FontFamily="Cambria" FontSize="16" Grid.Row="0"/>
        <TextBox x:Name="ReplaceWith" Text="Replace With" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Stretch" FontFamily="Cambria" FontSize="16" Grid.Row="1"/>
        <Grid Grid.Row="2">
            <Grid.ColumnDefinitions>
                <ColumnDefinition/>
                <ColumnDefinition/>
            </Grid.ColumnDefinitions>
            <CheckBox x:Name="MultLineOpt" Content="Multiline?" HorizontalAlignment="Center" VerticalAlignment="Center" Grid.Column="0" IsChecked="True"/>
            <CheckBox x:Name="DotMatchNL" Content=". matches newline?" HorizontalAlignment="Center" VerticalAlignment="Center" Grid.Column="1" IsChecked="True"/>
        </Grid>        

    </Grid>
</Window>