CDialogBar: moves content (windows) when docked at left side

Hi
 
I have a question concerning the CDialogBar (:CControlBar).
 
I habe a MDI application with a dockable toolbox (CDialogBar).
The user is able/allowed to move the DialogBar and to dock it at the right or left side
 

When I dock at the left side, the content of the mdi-application (all open windows) are moved right (so the dockable bar moves the windows).
 
If i dock at the right side, nothing changes.
 

How can I change the behaviour of the bar, that the windows inside the application keep the same position when I dock left ??
 

 
(Problem is, that my windows are aligned on the right side of the application). When I dock the bar on the left, the windows are getting moved in the not visible area.)
 

 
Thanks in advance fpr your help