private void RadGridView_Copied(object sender, Telerik.Windows.RadRoutedEventArgs e)
{
	string copiedData = Clipboard.GetText();
	int headerEndIndex = copiedData.IndexOf("\r\n");
	string headerString = copiedData.Substring(0, headerEndIndex) + "\r\n";
	copiedData = copiedData.Remove(0, headerEndIndex);

	var gridView = (RadGridView)sender;
	var filteredColumns = gridView.Columns.OfType<Telerik.Windows.Controls.GridViewColumn>()
		.OrderBy(x => x.DisplayIndex)
		.Where(x => x.IsVisible && !excludedColumns.Contains(x));
	// Where excludedColumns list contains the columns that shouldn't be copied. In this example, this collection is used in the CopyingCellClipboardContent event handler to remove the corresponding columns from the clipboard copy process.

	string newHeader = string.Empty;
	for (int i = 0; i < filteredColumns.Count(); i++)
	{
		var column = filteredColumns.ElementAt(i);
		newHeader += column.Header.ToString();
		if (i < filteredColumns.Count() - 1)
		{
			newHeader += "\t";
		}

	}
	copiedData = newHeader + copiedData;
	Clipboard.SetText(copiedData);
}

<telerik:RadGridView x:Name="clubsGrid" ItemsSource="{Binding Foos}" AutoGenerateColumns="False">
	<telerik:RadGridView.Columns>
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo1}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo2}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo3}" Width="*" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo4}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo5}" MinWidth="100" />
		<telerik:GridViewDataColumn DataMemberBinding="{Binding Foo6}" MinWidth="100" />
	</telerik:RadGridView.Columns>
</telerik:RadGridView>

<DataGrid ItemsSource="{Binding Foos}" AutoGenerateColumns="False" Grid.Row="1">
	<DataGrid.Columns>
		<DataGridTextColumn Binding="{Binding Foo1}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo2}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo3}" Width="*" />
		<DataGridTextColumn Binding="{Binding Foo4}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo5}" MinWidth="100" />
		<DataGridTextColumn Binding="{Binding Foo6}" MinWidth="100" />
	</DataGrid.Columns>
</DataGrid>