From the Zend_Gdata documentation:
<?php
$query = new Zend_Gdata_Spreadsheets_ListQuery();
$query->setSpreadsheetKey($spreadsheetKey);
$query->setWorksheetId($worksheetId);
$query->setSpreadsheetQuery('name=John and age>25');
$listFeed = $spreadsheetService->getListFeed($query);
?>
And to setup the $spreadsheetService
object:
<?php
$service = Zend_Gdata_Spreadsheets::AUTH_SERVICE_NAME;
$client = Zend_Gdata_ClientLogin::getHttpClient($user, $pass, $service);
$spreadsheetService = new Zend_Gdata_Spreadsheets($client);
$feed = $spreadsheetService->getSpreadsheetFeed();
?>
You'll need to download either the full Zend Framework, or the standalone Google Data library.