Show order number in payment info section of order confirmation e-mail

When a customer chooses to pay using Direct Bank Transfer, the order e-mail confirmation shows the bank code, swift code, etc. they need to use. I have added a field there called reference number that they should use when sending the transfer. I would like the reference number to be their order number. I have tried a few different things, but the order number doesn't show in the e-mail confirmation. This is what I currently have in includes/languages/english/modules/payment/dirbank.php:

define('MODULE_PAYMENT_DIRBANK_TEXT_EMAIL_FOOTER',
"Please use the following details to transfer your total order value:\n\n" .
"\nAccount No.: " . MODULE_PAYMENT_DIRBANK_ACCNUM .
"\nBSB Number: " . MODULE_PAYMENT_DIRBANK_BSB .
"\nAccount Name: " . MODULE_PAYMENT_DIRBANK_ACCNAM .
"\nBank Name: " . MODULE_PAYMENT_DIRBANK_BANKNAM .
"\nReference No: " . $zv_orders_id . );

I am just not sure what to use there to get the order number.

Thanks!

You've got a define in a define and trying to insert a result where the file is looking for another define.
Quick thought is to look at the file that defines the other MODULE_PAYMENT_DIRBANK_.... defines and define something like MODULE_PAYMENT_DIRBANK_BANKORDER as $zv_orders_id.

Or use a printf function and associated reference to echo the above definition.

Ie:

define('MY_CONSTANT', 'info to display and order_id: %s');

In presentation:

printf(MY_DEFINE, $zv_orders_id);

Reason is that language definitions are called before the associated data is made available, so basically the $zv_orders_id is null at the time the define is processed. The above was shown with a single variable; however, if there are two or more and it is designed to possibly use more than one language, then would want to use a sort of reference for each such use so that they can be resequenced within the define and the assigning printf function can remain unchanged.

Consider this change I recommended in the AUS version of the Direct Bank Deposit module:
https://www.zen-cart.com/showthread.php?220590-Bank-Transfer&p=1325229#post1325229

DrByte:

Consider this change I recommended in the AUS version of the Direct Bank Deposit module:
https://www.zen-cart.com/showthread.php?220590-Bank-Transfer&p=1325229#post1325229

Perfect, thank you!