In the custom module i've made a simple modification that enable the use
of chroot in &file_chooser_buton (types 5 and 6).
This modification allows to restrict the path to the files in the
file_chooser_button from a custom command.
The restircted path was that you enter as option in the variable
definition type file or directory (5 or 6).
I'va included the two cgi's modified.