Hi,
Well, it will be more a bridge between Magento and HikaShop than a bridge with HikaMarket.
I don't see all the requirements but I know that you can already use the CSV import or the import using Mass action in order to import or update products.
So, thinking about a way to export e CSV from Magento and import it into HikaShop to update the product stock ; is not something impossible but for sure it will require some analyzes, some time and some tests to do it right.
After that, I do not have knowledge on Magento so I can't really say more.
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.