my $mydir = 'Where/the/directory/is';

opendir (MYDIR, $mydir) or die "Could not opendir $mydir: $!\n";
my @numfiles = grep { /^\d{4}.*\.html$/} readdir MYDIR;
closedir(MYDIR);

print "<UL>\n";
for (@numfiles) {
  print qq! <LI><A HREF="$_">$_</A></LI>\n!;
}
print "</UL>\n";