After adding a handler, the next step is to set focus to the cell (if any) under the mouse click.
this.AddHandler(MouseLeftButtonDownEvent, new MouseButtonEventHandler(this.myRadGridView_MouseDown), true);
I can set the cell focus given row and column.
The goal is to find the UIElement under the mouse click, if any, and then attempt to set Focus to it.
Thank you for your assistance.