try:

 
  $list->see(99) ;
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this was from perldoc Tk::HList
$hlist->see($entryPath)
Adjust the view in the HList so that the entry given by $entryPath is visible. If the entry is already vis­ ible then the method has no effect; if the entry is near one edge of the window then the HList scrolls to bring the element into view at the edge; otherwise the HList widget scrolls to center the entry.

My version of your list:

use Tk;
use Tk::HList;
use strict;
use warnings ;
my $i;
my $mw = MainWindow->new(-title => "HList Example");
my $list = $mw->Scrolled("HList",
                         -header => 1,
                         -columns => 1,
                         -scrollbars => "ose"
                         )->pack;
$list->header('create', 0, -text => "Num");
for ($i = 0 ; $i < 100 ; $i++) {
   $list->add($i);
   $list->itemCreate($i, 0, -text => $i);
}
$list->see(99) ;
MainLoop;
[download]

Enjoy!