Ok, a few things:
1. Rune, the author of this shop, is currently inactive, so you might just want to post a normal request.
2. The digits in hex are ordered [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F] numbers then letters
Sounds like an easily doable event/script. Hope someone helps you.