This posting is older than 6 months and can contain outdated information.
Thanks for asking.
There's a reason, though, why that feature is not found in Remote Buddy.
The Wiili.org wiki already says it well, so I'll just quote it here.
-- Quote: http://www.wiili.org/Wiimote#IR_Sensor --
[..]
During R&D, Nintendo discovered the motion sensors were not accurate
enough to use the remote to control an on-screen cursor. To correct
this, they augmented the remote with an infrared image sensor on the
front designed to locate two IR beacons within the controller's field
of view. The beacons are housed within a device misleadingly called
the Sensor Bar.
These two sources of IR light are tracked by a PixArt sensor in the
front of the Wiimote housing. By tracking the locations of these two
points in the sensors 2D field of view, the system can derive more
accurate pointing information.
[..]
-- End of quote --
My own tests showed me that the accellerometers are not a good data
source for implementing a virtual mouse - at least if you really want
to use it beyond a technical demo. I was regularly faster at
positioning the mouse cursor using just the remote's buttons and
Remote Buddy's "normal" virtual mouse.
Best regards,
Felix Schwarz