Sort threads from sql

[webForum-dev]

Hello, I want to maintain the same sortorder in forumdisplay as default for paging and such (latest threads first), but I want to sort the threads returned by the database with php.

I thought I could use $sortfield for that, but I have tried this code

$sortfield = "thread.title";
$sqlsortfield = 'lastpost';
$handled = true;

booth in the forumdisplay_start and the forumdisplay_sort, but it just won't work.