Hi,
With that kind of code ; you cannot.
But it will be possible in HikaShop 3.
You have the latest version of HikaShop ; so you have the version 2.6.1
So you do not have HikaShop 3 ; which is fully logical because we are still working on that development.
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.