[Paul M]

There are too many single quotes in that.

Since it's only one column try this ;

PHP Code:

$choc = $vbulletin->db->query_first("
    SELECT column1
    FROM " . TABLE_PREFIX . "test
    WHERE columnfudge > '999'
    LIMIT 1
");  

$chocolate = $choc['column1'];

$vbulletin->db->query_write("
    INSERT INTO " . TABLE_PREFIX . "test (column1,columnfudge) VALUES ('[2] $chocolate','0')
");  

$vbulletin->db->query_write("
    UPDATE test SET column1 = '[1] $chocolate' WHERE CONVERT( `column1` USING utf8 ) = 'abc'
");  

log_cron_action('Hard thing done', $nextitem);