A question about buying NX

hey guys.

ive noticed that when i buy nexon game cards in the store, and then redeem them on line, you get 'nx prepaid', and that when you charge nx on line, paying through paypal or whatever the other payment option is, you get 'nx credit'.

ive noticed (as im sure most of you know) that there are certain items that you can only use 'nx prepaid' for, and you cant gift items using 'nx credit' (i put all my nx on my legit account, and then when i want to buy something on one of my hacking accounts, i simply log on to my legit account, and gift myself, that way i dont load up 25 or 50 bucks worth of nx onto my hacking account only to log on one day and find that its been banned :\ ).

now, here is my question :

is there any way to buy nx on line, like through paypal or whatever, and get it to count as 'nx prepaid'?
i googled quite a bit, and a couple of weeks ago i found a tutorial that explained a way to do it, but it was a late night and i was really tired, so i just skimmed over it, and didnt pay it much attention. now i cant find the site again. even though the store is less than a mile from my house, it is so much easier for me to buy it on line. plus, half of the time when i realize i need to re-up on some nx, its like 2 or 3 in the morning, and im sure as hell not driving up to the store at that time to just to get a damn gaming card!

so does anyone know of a way to do this? i am almost sure it is possible, i just have yet to figure out how to do it myself.

thanks guys, in advanced, for your time and your help.

happy hacking!