Resizable NetDockableDialog docked extents

Hi, I am trying to set docked extents for resizeable NetDockable dialog without luck...

In .NET this can be handled by MinimumSize property of attached control, but what to use in MDL/MFC?

I have used mdlNativeWindow_getNETDockedExtents and in SecondaryDialogHook have it set, but without luck...

This is what I do for wanted region:

        RECT rect;
        GetClientRect(m_hWnd, &rect);     
        dmP->u.dockedExtent.dockExtent.x = rect.right;
        dmP->u.dockedExtent.dockExtent.y = rect.bottom;
        dmP->u.dockedExtent.extentFlag = DOCKEXTENT_SPECIFIED;

This for unwanted:

dmP->u.dockedExtent.extentFlag = DOCKEXTENT_INVALIDREGION;

Unwanted regions are disabled, but docked extents are still about 100 units in width and my dialog has 200 units width at least.

Should it work?

Dan