Spreadsheets, driven by code.

<?php

require 'vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\NamedRange;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

$spreadsheet = new Spreadsheet();
$worksheet = $spreadsheet->getActiveSheet();
$worksheet->setTitle('Sales');

$worksheet->fromArray([
    ['Item', 'Amount'],
    ['Keyboard', 40],
    ['Monitor', 190],
    ['Mouse', 25],
    ['Webcam', 55],
], null, 'A1');

$worksheet->setCellValue('D1', 0.20);

// Define the names: one range, one single cell. Absolute references.
$spreadsheet->addNamedRange(new NamedRange('Amounts', $worksheet, '$B$2:$B$5'));
$spreadsheet->addNamedRange(new NamedRange('TaxRate', $worksheet, '$D$1'));

// Formulas refer to the names.
$worksheet->setCellValue('D3', '=SUM(Amounts)');
$worksheet->setCellValue('D4', '=SUM(Amounts)*TaxRate');
$worksheet->setCellValue('D5', '=SUM(Amounts)*(1+TaxRate)');

(new Xlsx($spreadsheet))->save('named-ranges.xlsx');
echo "Wrote named-ranges.xlsx\n";

echo "Subtotal  =SUM(Amounts)            : " . $worksheet->getCell('D3')->getCalculatedValue() . "\n";
echo "Tax       =SUM(Amounts)*TaxRate    : " . $worksheet->getCell('D4')->getCalculatedValue() . "\n";
echo "Total     =SUM(Amounts)*(1+TaxRate): " . $worksheet->getCell('D5')->getCalculatedValue() . "\n";