[TYPO3] change meta tags dynamicly

[aowen at swissonline.ch]

i want to change the metatags keywords & description in my php-script wich i've included with the extension lumophpinclude. i've found the variables:

$GLOBALS["TSFE"]->currentPageData['setup']['lib.']['page.']['meta.']['keywords']
$GLOBALS["TSFE"]->all['pSetup']['meta.']['keywords']

I can change them but the changes dont occur to the html-document. their probably done to late.

Does anyone know how the change these tags?