Maybe I dont understand the question, but if you are in Mtext, you should be able to highlight the group of text in the Mtext editor and use the justification to align it to where you need.
In 2006 version, you have a 6 buttons for vertical/horizontal justificaion for quick changes. For the ability to fine tune the alignment, you can use tabs like you would in Word. I have used alignment lisps for dtext bceause it was difficult to move groups of dtext to the same location.
If there are several paragraphs of mtext(different objects), it is easier in my opinion to put that Mtext in one paragraph, as opposed to several. If it extends too far down, then make a new Mtext paragrapgh.
Hope this helps.