[TYPO3-mvc] post processing a BE record input (FED?)

[Sy Moen]

If I use the usual create or new action through the frontend it is very
simple to post-process input data... which I do a lot in an extension I am
working on.

But, I do not (yet) understand tceMain well enough to figure out how to do
the post processing in the BE if the record is added there. Is there a way
to add userFunc post processors in the TCA?

Or (even better?) with the new Page and FCE elements in FED[1], can I edit
the create / new actions for the backend just as I do with the extbase
frontend? Maybe (hopefully) using the same create / new action in both
places?

[1] http://fedext.net/fluid-typo3/