Oh sorry abou tmy miss undesrtanding, in Maya 4.5 there is a new node that allow you to have a locator with a string attribute that can have user defined text:
CREATE > ANNOTATION
This should do what you like, I hope. Otherwise I do not think that there is other way in MEL. I do not have maya in front of me right now but if you look in the whats new in 4.5 you'll see the annotation, the text will always face the camere as well.
Hope this help.
-a