m/AltaVista found (\d+,?\d*) results/;

should match it. See perldoc perlre for what ? and * do. Also have a look at perldoc perlretut.

Sören

Edit:
There seems to be no node for perlretut here yet. Edited to point to perldoc.com. Anyway, perlre is the better match for this question.