Well, MT is pretty standard (that’s why it was included)- but beyond that, it there isn’t much of a standardized import/export format.
It’s hard for me to give examples of how to get it in MT format because I don’t know the table structure- so I don’t have any idea of the queries you’ll need to get the data out. Check this page- it’s an overview of MT format. Basically, you just need to get the data into this format- same spacing, dashes, etc- and save it as a text file. But I don’t know the tool, so I’m not sure how you could go about it. Pure php would do it- looping through query results- but without knowing the db structure, I couldn’t guess as to the queries.