Hide Checkboxes in Picker / Listing

Hello everyone!
I started writing my first more complex extension and it's going pretty well. There's just one thing I can't get around, it seems.

I want to hide some of the selection boxes when the user edits multiple entries. There's a field in my database that is either 1 or 0 and depending on that, the box should be shown (1) or hidden (0). I tried duck-taping a solution using the search field but sadly, I can't see a way to modify the search value while the DCA is being processed. Before, I had the hopes of finding a similar function to paste_button_callback but there's none.

On the left: What it looks like now. On the right: What it should ideally look like.


https://dl.dropboxusercontent.com/u/...0/question.jpg



Thank you in advance!

So after playing around with the search field idea a little longer I realized that I could simply alter the Session depending on a GET flag in the DCA's OnLoad like so:

PHP Code:

---

// check GET-Flag, change the session to display only allowed items
$arr_SearchNew = $this -> arrObjects['Session'] -> get('search');

if(isset($_GET['t']))
{
    $arr_SearchNew['tl_collected_headers']['value'] = ID_ONE;
} else {
    $arr_SearchNew['tl_collected_headers']['value'] = ID_TWO;
}
// Set the field name used in the search
$arr_SearchNew['tl_collected_headers']['field'] = 'fieldName';

$this -> arrObjects['Session'] -> set('search', $arr_SearchNew); 


---

As a peculiarity, I had to change the 0 fields in the database to 2, otherwise the search would not be executed.
This way of doing things removes the tree structure of course - It's a hacky solution, what'dya expect?!
Hope that helps anyone with the same problem.