I currently have a TabControl set up for my WPF application in the form:

<TabControl Background="Transparent" BorderThickness="0" BorderBrush="{x:Null}" Padding="0">
    <TabItem Width="100" Header="Home" Background="Transparent" FontSize="20" BorderThickness="0" BorderBrush="{x:Null}"></TabItem>
    <TabItem Width="120" Header="Support" Background="Transparent" FontSize="20" BorderThickness="0" BorderBrush="{x:Null}"></TabItem>
    <TabItem Width="100" Header="Help" Background="Transparent" FontSize="20" BorderThickness="0" BorderBrush="{x:Null}"></TabItem>
</TabControl>

However, I wish to add other UI elements on top of this tab bar such as an expander and a TextBlock which are right aligned. I have tried messing with the dimensions of the TabControl property, but that affects the size of the content displayed on the tab as well.

How can I add elements on top of this tab bar without affecting the content displayed by it?