Hi,
That is unfortunately, not a case that HikaSerial can handle like that.
The goal of HikaSerial is to generate unique data (named "serial") when products are bought.
Implementing such feature would require some custom development.
And if you create a plugin in HikaShop to handle that workflow, the usage of HikaSerial will be piratically none because if you can ask HikaSerial to generate a "coupon" serial, you can directly generate a coupon in HikaShop...
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.