BackStage and Tab and ControlTab issue

I have my app with the BackStage all set as I want and everything is working. I need to maek sure users can tab through and ge tto everything.

Want to mimic Microsoft Word - Backstage Buttons/ Tabs do NOT use tab navigation. Can use ControlTabnavigation for BackstageTabs only. The selected BackstageTab has the TabNavigation within it's content

I tried this in very many differnt combination of keyBoardNaigation attached property and can't get it.

Very simple code:

<apribbon:Ribbon.ApplicationMenu>
	<apribbon:Backstage KeyTipAccessText="F">
		<apribbon:BackstageButton Command="ApplicationCommands.Help" KeyTipAccessText="F1" />
		<apribbon:Separator />
		<apribbon:BackstageTab Header="Open" KeyTipAccessText="O" ToolTip="{x:Null}">
			<Border>
				<DockPanel Margin="19,9">
					<!-- Content here that I need to be able to tab through -->                              
				</DockPanel>
			</Border>                       
		</apribbon:BackstageTab>
		<apribbon:BackstageButton Command="ApplicationCommands.Save" KeyTipAccessText="S" />
		<apribbon:BackstageButton Command="ApplicationCommands.SaveAs" KeyTipAccessText="A" />
		<apribbon:BackstageTab Header="Options" KeyTipAccessText="T" ToolTip="{x:Null}">
			<Border>
				<DockPanel Margin="19,9">
					<!-- Content here that I need to be able to tab through -->                              
				</DockPanel>
			</Border>                       
		</apribbon:BackstageTab>
		<apribbon:BackstageTab Header="Send" KeyTipAccessText="M" ToolTip="{x:Null}">
			<Border>
				<DockPanel Margin="19,9">
					<!-- Content here that I need to be able to tab through -->                              
				</DockPanel>
			</Border>                       
		</apribbon:BackstageTab>
		<apribbon:BackstageButton Command="ApplicationCommands.ApplicationExit" KeyTipAccessText="X" />
	</apribbon:Backstage>
</apribbon:Ribbon.ApplicationMenu>

Of course this is a simplified version - When the backstage is showing ONLY to be able to ControlTabNavigate through the BackstageTabs and tab navigation to be only internal to the content - this is same as Microsoft Word.

Any help would be appreciated.