[TYPO3] Modifying $_GET array before a page is rendered

[Vlatko Surlan]

Hi list. What I've been looking how to do is, in short, a TS equivalent of doing this:

$_GET['param'] = value

I need this in order to manipulate output from an extension that uses a global GET parameter
instead of a pi var: www.domain.com/index.php?id=43&album=1

That album=1 belongs to the extension. As it is not a pi parameter I cannot affect it via
_DEFAULT_PI_VARS. So I need a way to add the $_GET['album'] = 1 via TypoScript before the
extension begins to render. I thought this would be trivial, but after one day of trying
I changed my mind. Any help, hints or examples are greatly appreciated.