all, change to Expert Mode by pressing F2.
To reverse a sort order just place a "-"
in front of the sorting letter.
sorts by name (a-z) and "-n"
sorts reversed (z-a).
sorts by extension then by name.
sort by reversed extension then by name.
sorts by extension then by reversed name
sorts by reversed extension and then by reversed
These are just examples. You can put "-"
in front of every letter you like.