Xenon,
You can change the position of the label with a property node.Select properties>>label>>position.
However there is no way to change the justification programmatically. I can tell you how to change the font, size, or style, but there is not way to set the justification from the diagram, only on the front panel.
You could probably submit that as a request for future versions of LabVIEW. Go to this link:
http://sine.ni.com/apps/we/nicc.call_me?p_action=country&p_lang_id=US
and select product feedback.
Regards,
Cyril Bouton
Applications Engineer
National Instruments
Cyril Bouton
Active LabVIEW Developper