I believe you have to add scripts in /etc/acpi/events
example taken from /usr/doc/acpid-1.0.4/samples/panasonic:
script name: /etc/acpi/events/hotkey
Code:
# /etc/acpi/events/hotkey
# This script handles hotkey events on Panasonic notebooks
event=HKEY.*
action=/etc/acpi/hotkey.pl %e
Of course for this script, you have to copy /usr/doc/acpid-1.0.4/samples/panasonic/hotkey.pl in /etc/acpi/