Customer chooses HOW MANY points to apply

-- url of the page with the problem -- : mywebsite.com/mypage
-- HikaShop version -- : 2.3.0 Essentials
-- Joomla version -- : x.x
-- PHP version -- : x.x.x
-- Browser(s) name and version -- : XXXXX x.x.x
-- Error-message(debug-mod must be tuned on) -- : Error_message

I like to give my customers 100% of their points to use on checkout if they have Alphauser points
Therefore, the system will apply all the points they have, if necessary, to make the order FREE or greatly reduce the price.

I have no problem with that.

However, I WOULD like for the customer to determine how much they would like to apply.

For instance, if the order is $25 and they have enough points to make the order $5 (but in doing that it uses up ALL their points and are left with no points.

BUT, if they were given the option to use let say... only $10 worth of their points now and save the other $10 that would have been applied until later.... they could save some for later on another purchase down the road..

Is it possible?