Joomla is a wonderful platform to publish websites. With readily available templates you can have your website up and running in no time. Sometimes though you may need to direct your visitors to a different page than your regular home page, for instance you may want to direct all the visitors to a promotion page during special sales events. There is a very simple and easy way of doing this in Joomla.
Create and upload the standalone webpage to your domain.
Backup your index.php file in templates/YOUR_TEMPLATE_FOLDER.
Add following lines to the index.php file under the templates/YOUR_TEMPLATE_FOLDER.
Now when the visitors come to your website they will be taken to NEW_PAGE.php.
After the need to redirect the traffic is over simply replace the index.php file with the file you backed up in step 1.