How to configure the sensitivity of the Lenovo trackpoint joystick in ubuntu linux

To test :
$ sudo -s
# echo -n 200 > /sys/devices/platform/i8042/serio1/serio2/sensitivity

to change permanently :
$ sudo vim /etc/rc.local
and add the line :
echo -n 200 > /sys/devices/platform/i8042/serio1/serio2/sensitivity