How to freeze last column in WPF datagrid?

Having two DataGrids next to each other, with the right one having just the column you want to be fixed.

<Window x:Class="FrozenGrid.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="450" Width="800">
    <DockPanel Margin="50">
        <Slider DockPanel.Dock="Bottom" Value="5" Minimum="0" Maximum="6" 
                TickFrequency="1" IsSnapToTickEnabled="True" ValueChanged="OnSliderSlided" />

        <DataGrid DockPanel.Dock="Right" Name="_frozen" BorderThickness="0,1,1,1" AutoGenerateColumns="False" ScrollViewer.ScrollChanged="OnFrozenScrolled" HorizontalScrollBarVisibility="Visible">
            <DataGrid.Columns>
                <DataGridTextColumn Binding="{Binding [5]}" Header="F" />
            </DataGrid.Columns>
        </DataGrid>
        <DataGrid Name="_grid" AutoGenerateColumns="False" VerticalScrollBarVisibility="Hidden" ScrollViewer.ScrollChanged="OnGridScrolled">
            <DataGrid.Columns>
                <DataGridTextColumn Binding="{Binding [0]}" Header="A" />
                <DataGridTextColumn Binding="{Binding [1]}" Header="B" />
                <DataGridTextColumn Binding="{Binding [2]}" Header="C" />
                <DataGridTextColumn Binding="{Binding [3]}" Header="D" />
                <DataGridTextColumn Binding="{Binding [4]}" Header="E" />
            </DataGrid.Columns>
        </DataGrid>
    </DockPanel>
</Window>

using System;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace FrozenGrid
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            double[][] data = new double[50][];
            Random random = new Random();
            for (int i = 0; i < 50; i++)
                data[i] = Enumerable.Range(0, 10).Select(r => random.NextDouble()).ToArray();

            _grid.ItemsSource = data;
            _frozen.ItemsSource = data;
        }

        private ScrollViewer _gridScroll;
        private ScrollViewer _frozenScroll;
        private void OnGridScrolled(object sender, ScrollChangedEventArgs e) => OnScrolled(_frozen, ref _frozenScroll, e);
        private void OnFrozenScrolled(object sender, ScrollChangedEventArgs e) => OnScrolled(_grid, ref _gridScroll, e);
        private void OnScrolled(DataGrid targetGrid, ref ScrollViewer targetScroll, ScrollChangedEventArgs e)
        {
            if (targetScroll == null)
                targetScroll = (ScrollViewer)VisualTreeHelper.GetChild(VisualTreeHelper.GetChild(targetGrid, 0), 0);  // Grid > DG_ScrollViewer

            targetScroll.ScrollToVerticalOffset(e.VerticalOffset);
        }

        private void OnSliderSlided(object sender, RoutedPropertyChangedEventArgs<double> e)
        {
            if (!IsInitialized)
                return;

            if (e.NewValue > e.OldValue)
            {
                int freeColumns = (int)(e.NewValue - e.OldValue);
                for (int i = 0; i < freeColumns; i++)
                {
                    DataGridColumn c = _frozen.Columns.First();
                    _frozen.Columns.Remove(c);
                    _grid.Columns.Add(c);
                }
            }
            else
            {
                int fixColumns = (int)(e.OldValue - e.NewValue);
                for (int i = 0; i < fixColumns; i++)
                {
                    DataGridColumn c = _grid.Columns.Last();
                    _grid.Columns.Remove(c);
                    _frozen.Columns.Insert(0, c);
                }
            }

            _grid.Visibility = _grid.Columns.Count > 0 ? Visibility.Visible : Visibility.Collapsed;
            _frozen.Visibility = _frozen.Columns.Count > 0 ? Visibility.Visible : Visibility.Collapsed;
            _grid.VerticalScrollBarVisibility = _frozen.Columns.Count < 1 ? ScrollBarVisibility.Visible : ScrollBarVisibility.Hidden;
        }
    }
}