No news concerning the ability to create or delete directories in (actually useless) Rl-Flash library ?
you can create a folder by specifying a path to a file that contains the folder in a call to 'fopen'. FlashFS is a nice tool, which has a couple of totally useless features such as a RAM "drive", that is initialized to 0 when formatted. brilliant, not? try to connect that one to a USB device, it does wonders :-(. It pissed me of that I still to write a FAT12 file system in the coming 4 weeks or so, along with the rest of the work I have to do!).
Did you take a look to Fatfs ? I don't know if it manages Fat12 but it's working pretty well. elm-chan.org (without http://www.)