Is there some special text to right align text, like there is for centering?
Using the overlap front symbol (provided for you in X-tra/Starforge) will align text to the right if you use it before the text.
Another comment:
Overlapping back centers the text, overlapping front aligns it to the right. Stacking is another story.
And some history;
The "Back Mark" is not the true name. It's actually called the Center Align mark. Same with "Front Mark" being right align. Don't let these names fool you. If someone puts the mark in your face, you shouldn't say it's the back or front mark, because those don't exist. You should say it's the center align or right align mark.