It is built using the thread datamanagers.
The best way to handle it would be:
- add fields to the newthread template
- clean the variables in newthread_post_start ($vbulletin->input->clean_array_gpc()
- add fields to database using another query in newpost_complete eg
PHP Code:
if($type == 'thread')
{
$vbulletin->db->query_write("DO YOUR QUERY HERE"); # $threadinfo['threadid'] for the new threadid.
}
Or it could very well be possible by modifying the datamanagers, but I'm not that far into the system yet