Hi,
The "redirect fallback" plugin is there to catch URL which are pointing to "com_virtuemart", read the product id and redirect the user to the corresponding product in HikaShop.
This plugin has mostly been made to migrate from VM to HikaShop in the same website.
For "new" websites, where VirtueMart won't be installed at all, you should use a third party extension in order to transfer your old URL from your old website to new url in your new.
Because you're building a brand new website, the won't be able to keep all pages with the exact same URL ; so you have to list URL (or pattern url) to make your compatibility.
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.