Draw rectangle from right to left

Question

Hi everybody,
 
I want to draw some rectangles from right to left on a Panel wich is on TabControl
TabControl.RightToLeft : yes
TabControl.RightToLeftLayout : true
I use : 
Point.Location= new system.drawing.point(x,y);
Point.size=new system.drawing.size(width, height)
these rectangles must be drawn from right to left according with TabControl, with certainly a loop for
Thank you very much for your help