Hello,
Using the "Order number format" option through "Hikashop->System->Configuration->Main" will probably do the job.
Also, note that you'll find more information about that option through the
documentation
:
Order number format : This option enables you to set the format of order numbers. It is only available in commercial versions of HikaShop. By default, the order number uses letters and numbers interleaved together. this is represented here with the tag {automatic_code}. If you want to use the order number directly, you can use the tag {id}. In the tag id, you can specify the number of numbers with the size attribute. For example, {id size="5"} will result in 00123 for the order with the id 123. You can also use the date tag in order to insert date information. For example, {date format="m/Y"} will result in 02/11 for an order made in February 2011. You can combine them to generate pretty advanced order numbers like the format RE-{id size="5"}/{date format="m/Y"} used for German accounting which will result in RE-00123/02/11 for the order 123 made on February 2011.
