Is it possible to dock using code a dockpane just like the attached image?
Note the the dockpane is dock between the TOC and the catalog and NOT under them (taking the full width of the window).
The only option in the code put the new dockpane so it cover (or make shorter) the toc and catalog.
Well, go through this page here. I assume you already aware of the dock property but have also a look at the dockWith property.
A value of 'bottom' for the dock property should do the trick...