use constant CONFIG_ITEMS => [ qw( 
  server            database             user 
  password          logdir               basedir 
  inputdir          inputextension       cleanupdays 
  countyid          unzipdir             sleeptime 
  unzipdir          mail_host            support_addr
  ar_court_text     ar_court_ori         debug_print
  delete_txt_file   from_email_address   to_email_address
  send_email        init_version
] );

my %config;

foreach my $item ( CONFIG_ITEMS ) {
  my $value = $cfg->param($item);
  help($item) unless defined $value and length $value;
  $config{$item} = $value;
}

sub help {
  die "Parameter $_[0] wasn't set in config file.";
}

##</code><code>##

use constant CONFIG_ITEMS => {
  server   => sub { my $param = shift; ...some Boolean test },
  database => sub { ... },
  user     => ...
};

##</code><code>##

use constant CONFIG_ITEMS => {
  server => qr/some pattern/,
  database => qr/some pattern/,
  ...
};

##</code><code>##

foreach my $item( keys %{CONFIG_ITEMS} ) {
  my $value = $cfg->param($item);
  help() unless CONFIG_ITEMS->{$item}->($value);
  $config{$item} = $value;
}