my %users;
while (<CSV>) {
    next if ($. == 1);
    if ($csv->parse($_)) {
        my @columns = $csv->fields();
        my @choppedcols = $csv->fields();
        
        my $username =  lc($columns[1]);
        $users{$username}{first_name} = ($columns[2]); 
        $users{$username{last_name} = ($columns[3]);
        # etc... then
        my $telephone = ($columns[8]).-($columns[6]);
        if ($columns[8] == 1) {
            $users{$username}{fax_number} = $telephone;
        }
        else {
            $users{$username}{phone_number} = $telephone;
        }
    }
}

##</code><code>##

for my $user (keys %users) {
    print "dn: uid=$user\n",
        "givenName: $users{$user}{first_name}\n",
        "sn: $user{$user}{last_name}\n",
        #etc...
        "telephonNumber: $users{$user}{phone_number}\n",
        "faxNumber: $users{$user}{fax_number}\n";
}