[TYPO3] TCEforms: dynamic column label in TCA?

[marcel.gsteiger at milprog.ch]

Hi all,

I'm new to typo3 programming and have just built my first extension that 
  allows to manage a simple table using TCEforms in 3 languages (german, 
french, italian).

I have a table with a type field and several additional fields. The 
additional fields only appear after the user has entered the type field 
and updated its form. This works nicely using TCA configuration. My 
backend users add records to this table using TCEforms.

The content in the additional fields always has the same meaning, but 
depending on the value in the type field, I would like to have TCEforms 
attach a label with a slightly different text.

I wanted to try something like adding in tca.php an assignment

$TCA["mytable"]["columns"]["mycolumn"]["label"]="LLL:EXT:myext/locallang_db.php:tx_myext_mytable.mycolumn_".$value_of_type_field

...and then add these different labels in locallang_db.php, but I don't 
know how I could get at the $value_of_the_type_field within tca.php.

Any help on how to accomplish this would much be appreciated.

Regards
--Marcel