You won't be able to use bindColumn for that. It does SQL injection checks, which will stop that from working.
I think the only solution would be to use a separate query with the same trigger to do the increment. Something like this above your current update record code:
<?php>
if (same if statement as your update) {
?>
<?php
$Recordset1 = new WA_MySQLi_RS("Recordset1",$localhost_i,0);
$Recordset1->setQuery("UPDATE tblName SET hitCount = hitCount + 1 WHERE id = 1");
$Recordset1->execute();
?>
<?php
}
?>