[TYPO3] User-Change Code AFTER page is loaded from cache

[Mark Schmidt]

Hi there!

I have a rather special problem, as I need to substitute a dummy-Tag 
within a page AFTER everything else is done in Typo3 - even the 
caching-algorithms.

So the idea is this:

1.) Typo3 does the generating of the page
2a.) Page is generated or
2b.) Page is fetched from cache
3.) My SCript subsitutes one or more markers in the HTML
4.) HTML is echoed out.

Can anyone give me a hint how to do this? Where is the actual HTML 
Content printed out on screen?

Thanks a lot for your help!

Mark