Hi,
Indeed, I don't understood the situation.
It's possible in HikaShop to put products from cart to wishlists thanks to the menu type "hikashop - showcart".
When in that menu, and with the desired options enabled in Configuration > Features > Wishlist, the customer can put some of the items to the wishlist, and change the quantity in his cart to purchase only one.
If you want an automated situation, it will require a custom plugin, here is some documentation:
hikashop.com/support/support/documentati...r-documentation.html