John,
At the top of the File->Open dialog, count the number of icons
from the LookIn box to the New Folder (not counting the LookIn
box itself). This can vary with your version of Word and with
whether you have any really nervy add-ins that reorder or add
to those icons. (I haven't seen such things since Word 95 but
they may still be around.) The shorcut key to "click" that
icon is ALT plus the number of icons counted.
On mine that button is 5 icons away. So pressing ALT+5 opens
the New Folder subdialog. And similarly for the other icons
in that row.
I've never seen this documented anywhere.
