InputGestureCollection inputsCopy = new InputGestureCollection();
inputsCopy.Add(new KeyGesture(Key.C, ModifierKeys.Control, "Ctrl+C"));
mnuCopy = new RoutedUICommand("Копировать", "MnuCopy", typeof(DataCommands), inputsCopy);

<CommandBinding Command="command:DataCommands.MnuCopy" Executed="MnuCopyCommand_Executed" CanExecute="CopyCommand_CanExecute"/>

<ContextMenu x:Key="CellContextMenu" Opened="OnCellContextMenu_Opened">
    <MenuItem x:Name="menuItemCopy" Header="Копировать" Tag="mnuCopy" Command="command:DataCommands.MnuCopy"/>