Not sure about that. I will look.
edit: It shows a text, but you cant define your own label to it.
Code:
[ExtrasButton]
------------------------------------------------------- Autorun\Extras.png \ ExtrasSelected.png \ ExtrasClicked.png
Left=375
Top=410
Width=68
Height=68
//AreaTop= // integer
//AreaLeft= // integer
//AreaWidth= // integer
//AreaHeight= // integer
//Font= // string
//FontColor= // $RGB
//FontColorOnMouse= // $RGB
//FontColorMouseDown= // $RGB
//FontColorDisabled= // $RGB
FontSize=8
//FontSizeOnMouse= // integer
//FontBold= // 0 / 1
//Alignment= // 0 / 1
//LabelX=-2000
//LabelY= // # pixels
Visible=1
To do so, you must edit language files in Subfolder Languages. Search there for Extras.