Increase Item Rect

Hi there

Im using the PLanner in Timeline mode. ie Header = Time, Sidebar = Names.
Im trying to increase the size of the certain Planner Items, ie increase the canvas size of the Item.Rect.
Ive tried a number of attempts eg :-
procedure TfLiveVisits.MyPlanner1ItemAfterPaint(Sender: TObject;
  Item: TPlannerItem; ACanvas: TCanvas; ARect: TRect);
ARect.Right  := ARect.Right + 10;

ACanvas.Brush.Color := clBlack;
This fails!!!! ie the Item.Right does not increase by 10
Ive also triied using Planner.OnAfterPaint eg
procedure TfLiveVisits.MyPlanner1AfterPaint(Sender: TObject);
Get item etc.....
r := item.ItemRect; <----- Get the item Rect
r.Right  := r.Right + 10;
MyPlanner1.GridControl.Canvas.Brush.Color := clBlack;                          MyPlanner1.GridControl.Canvas.FillRect(r)
This initially works, ie increases the Rect.Right.  However, when I scroll, it then fails miserably.
Do you have any ideas, how I can increase say Rect.Right of an item????

This is not really possible. 

First of all, other areas outside the PlannerItem need to be painted as well and can be painted AFTER the item is painted and would as such be painted on top of the painting to "extend" the item.
Secondly, a lot of functions rely on knowing the item size , in particular everything related with moue click detection, mouse operations,... so, drawing on a different size behind the back of the Planner will disturb mouse handling.

No problem.  Ill have to think of a work-around.  Many thanks for the quick reply.