Assigning a directory in SIO2IDE fdisk

Hi,

I'm trying to assign a directory that contains ATR files, using SIO2IDE FDISK.  This is so I can access ATR files and configure them to specific drive letters.

Unfortunately, all that I can assign is the root directory.  In FDISK, if I press D to change active directory, open the desired directory (at the top of the screen it says "UNKNOWN DIRECTORY"), then I press A to assign it, but it returns "NOT SIO2IDE DIR".

I can't find any specific guidelines as to acceptable directory names or how many files can be contained within them, etc.  I've tried a simple directory name like ATR with only a few files, but that does not work.

Does anyone have any insight to offer?  The ability to use ATR files seems like a fairly important feature.

Thanks