extendedareas-configuration-snippet.xml

<ext:extendedareas>
  <ext:add>
    <ext:extension assignid="FirstButton" name="Newest">
      <ext:control>~/Controls/ExtendedAreas/FirstButton.ascx</ext:control>
      <ext:pagetype></ext:pagetype>
      <ext:renderinblock>false</ext:renderinblock>
      <ext:apply>
        <ext:view name="TridionDashboard">
          <ext:control id="MainDeckPageButtons" />
        </ext:view>
      </ext:apply>
    </ext:extension>
  </ext:add>
</ext:extendedareas>