Hello,
HikaShop can store a number of points in a "user custom field" ; we call them "user points".
They are two plugins for "user points" (which are also compatible with AlphaUserPoints/AltaUserPoints/EasySocialPoints).
The first one allow to gain points when some products are bought.
The second one allow to create a discount by using the points.
Due to the specification of the very first "points" plugin and the fact that we have to keep some kind of retro-compatibility with these two plugins, their features are "limited" in the way that they can't evolve much ; specially because the second plugin is a "payment plugin" so it inherits the payment plugin features.
That's why, if you want to allow your customer to "transform" their points into a "free product" in their cart ; it would require the development of a specific (and custom) plugin.
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.