[Urgent]How to change PirateBox Shared Folder to USB by default

Hi,
I am enjoying the Piratebox on the Raspberry Pi, :)
but stuck on how to configure the Piratebox Shared folder to USB. :(
I have tried it by adding links but it didnt work I hope there may be the Permissions issue
I want the following directory to link with my Shared Directory in Usb

pi@raspberrypi ~ $ ls -lh  /opt/piratebox/share/Shared/
total 124K
-rw------- 1 nobody nogroup 120K May 12 09:44 07.png
drwxrwxrwx 3 root   root    4.0K May 12 09:24 Apps

My Shared directory on the usb is

pi@raspberrypi ~ $ ls -lh /media/usb0/
total 16K
drwxr-xr-x 2 root root 16K May 12 10:44 Shared

I need to make this Shared directory as default for Droopy server's file uploading and also the folder for default file storage.
please tell me the changes in /opt/piratebox/piratebox.conf and the user permissions and directory permissions.

thanks in advance