I suppose JEmplode will have to do it this way:

Split the 8-hex-digit FID into 5-digit subdir, and 3-digit subFID.

Try to access the files as /empeg/fids[01]/subdir/subFID
If that fails, then try /empeg/fids[01]/FID

When uploading, just use /empeg/fids[01]/FID and Hijack will convert it to a subdir (creating the subdir if need be) as required, if required.

-ml