Use /etc/xdg/lubuntu to store custom configuration files.

debian/changelog

@@ -6,6 +6,7 @@ lubuntu-default-settings (0.2) UNRELEASED; urgency=low
     the battery icon in notification-area
   * Set the terminal for pcmanfm to lxterminal
   * Move lxpanel background for Lubuntu to a specific file.
+  * Use /etc/xdg/lubuntu to store custom configuration files.
 
  -- Julien Lavergne <gilir@ubuntu.com>  Fri, 06 Nov 2009 18:58:46 +0100
 

usr/bin/startlubuntu

@@ -4,6 +4,15 @@ if [ -z "$XDG_CONFIG_HOME" ]; then
     export XDG_CONFIG_HOME="$HOME/.config"
 fi
 
+#Allow custom configuration files in /etc/xdg/lubuntu
+if test "x$XDG_CONFIG_DIRS" = "x"
+then
+  XDG_CONFIG_DIRS="/etc/xdg/lubuntu:/etc/xdg"
+else
+  XDG_CONFIG_DIRS="/etc/xdg/lubuntu/:$XDG_CONFIG_DIRS:/etc/xdg"
+fi
+export XDG_CONFIG_DIRS
+
 # Ensure the existance of pcmanfm config file
 PCMANFM_CONF_DIR="$XDG_CONFIG_HOME/pcmanfm"
 if [ ! -f "$PCMANFM_CONF_DIR/main.lubuntu" ]; then