12 digit coupon but only the last 5 should be taken into an account

I have a strange problem.

Approximately 250.000 people have a 12 digit number on their electrical bill. The idea is that with this number they get a 20% discount.

12 digit number = coupon code

Because they cannot give us 250.000 12-digit numbers we have to put in the system all the coupon codes. Which is impossible.

Is it possible for the system to take into an account only the last 5 digits of the 12 digit numbers which customers will fill in on the order page?

Coupon code: XXXXXXXX12345

Thank you for your help.

Actually is there a chance to have variables in the coupon code?

For example: only the first digit or character of the coupon code must be correct for the coupon to be viable.

Is it possible?

Hi, you would have to customize the code in order to do what you want. Specifically the file administrator/components/com_awocoupon/assets/virtuemart/ps_coupon_process.php.

if you need an estimate on the work please send me a private message with full detailsw.

Hi Seyi, you've got PM ;)
Thank you.