[Opserty]

Hook Location: newthread_post_start

PHP Code:

// Clean input
$vbulletin->input->clean_array_gpc('p', array(
        'url'       => TYPE_STR,
        'img'       => TYPE_STR,
        'info'      => TYPE_NOHTML,
        'trailer'   => TYPE_NOHTML
    ));
                    
// Assign the input to go to the builder
$newpost['url'] = $vbulletin->GPC['url'];
// Repeat for others 


Hook Location: postdata_start

PHP Code:

// Set our custom valid fields
$this->validfields['url'] = array(TYPE_STR, REQ_NO);
// Repeat for others 


Hook Location: newpost_process

PHP Code:

// Set the input data to the custom fields
$dataman->setr('url', $post['url']);
// Repeat for others 


Now you need to edit the newthread template with the correct input boxes which have the names 'url', 'img', 'info' and 'trailer'.

I hope I haven't missed anything out but I think that it is pretty much it.

EDIT: I don't know if you can overwrite the message text with the txtDesc using plugins. Why not just ask the user to input the description as the content of the post? It would be far easier to do it that way