use Data::Dumper;

my $list = [ "k0", "k1", "k2", ];
my ($h,$t);
$t = $h = {};
foreach my $k ( @{$list}[ 0 .. $#{$list}-1 ] ) {
    $t->{$k} = {};
    $t = $t->{$k};
}
$t->{$list->[-1]} = 'val';

print Dumper $h;
__END__
$VAR1 = { 
          'k0' => { 
                    'k1' => { 
                              'k2' => 'val'
                            }
                  }
        };