Touchscreen does not work on Fujitsu lifebook

For my 6 year old son, I resurrected a old Fujitsu lifebook laptop. I
installed Ubuntu 7.10 nd it runs great. Model B2620.

Except for one thing; this computer has a touchscreen and a special
pencil that you could use to touch the screen and emulate mouse
clicks.

Obviously enough, this feature sort of works: the mouse moves in
response to the pen. Except that it does not move correctly and does
not exactly track the pen, it moves horizontally only and, IIRC, even
that does not work well.

I would love this to work as, to me, this is a very convenient
feature.

Any idea if I can fix something?

i
.