use Modern::Perl;
use LWP::Simple 'get';

my $vendor = 'Rockwell Automation';
my $search_start = "<p><b>$vendor</b><br />";
my $search_end = '<p>&nbsp;</p>';

my $url = 'http://www.us-cert.gov/control_systems/ics-cert/archive.html';
my $html = get $url;

my ($section) = $html =~ /(\Q$search_start\E.*?\Q$search_end\E)/s;

print $section;