php excel Number Validation - php

Question

I am using php PEAR package to generate MS excel file to allow users supply data offline before uploading.
I need to carry out some numeric validation on specific cells. I want something like this:
cell 1: value<=5 (max=5)
cell 2: value<=10 (max=10)
cell 3: value<=15 (max=15)
My code:
require_once 'Spreadsheet/Excel/Writer.php';
$workbook = new Spreadsheet_Excel_Writer();
$filename = "Validate.xls";
$workbook->send($filename);
$worksheet =& $workbook->addWorksheet('Number validation');
$worksheet->write(0, 0, 'S/N');
$worksheet->write(0, 1, 'VALUE 2');
$worksheet->write(0, 2, 'VALUE 3');
$worksheet->write(0, 3, 'VALUE 4');
$worksheet->write(1, 0, '1');
$worksheet->write(1, 1, '0');
$worksheet->write(1, 2, '0');
$worksheet->write(1, 3, '0');
$workbook->close();
In my search I came across https://pear.php.net/manual/en/package.validate.validate.number.php but don't know how to modify the code above with
require_once 'Validate.php';
if (Validate::number(8.0004, array('decimal' => '.', 'dec_prec' => 4))) {
echo 'Valid number';
}
to make it validate the user input offline
Any help will be much appreciated