StDoodle
Minion
(and just have it insert the double brackets as needed)
I highly doubt that will work, as manually entering the square brackets results in them displaying as typed. Though I don't truly know where what is done. But don't worry too much about it; if it can't be reasonably worked out... ah well.
Also, fewyn had some issues with the new parser version today, and we're still seeing the occasional odd remnant with lots of error lines. No idea what's going on, but you might want to check out a few function pages and see if you can figure it out.