Lookup order info? or running a query and posting result back to the form?

I'm posting as my last option because I've searched and tried different hooks and code and I can't seem to get this to work. I'm using GF with WooCommerce to process a form.

All I want to do is to have Customer A place an order (without payment). Customer B will then go on, enter the order number to find out the cost, then go on to payment.

The last thing I tried is using the below code in the functions.php file but no luck:

[php]
add_filter('gform_field_value_cst', 'populate_order_fee');
function populate_order_fee($value){
    global $post;
	global $wpdb;

	$order_ID = $wpdb->get_var("SELECT post_id FROM database_table WHERE meta_value = '$_POST[ord];'");
	$order_total = $wpdb->get_var("SELECT meta_value FROM database_table WHERE post_id = $order_ID AND meta_key = '_order_total'");

    return $order_total;
}

"cst" is the parameter name for the field that needs $order_total.

Am I totally going about this the wrong way? Can GF even do this type of thing?
Basically I want to fill out the first field of a 1 field form -> run a mysql query to find the $order_total -> populate the second second field -> then go to payment.

Thanks in advance for any help.

Hi Chris,

I'm not sure I know how to run "debug statements" but when I run the code on its own (ie a separate script) and hard code the "$_POST[ord];" the query returns the $order_total.

So for example if I run:
$order_ID = $wpdb->get_var("SELECT post_id FROM database_table WHERE meta_value = 'order_1234567");

It works.

Also when I run:

$order_number = $wpdb->get_var("SELECT meta_value FROM database_table WHERE post_id = '151' AND meta_key = '_order_key'");

It will return the order number. It's labeled "_order_key" in the database.
So....I can get the query to work on its own, just not when included in the functions.php file.

Is it that the POST parameters are not being passed on?
Thanks.