Technicaly, an Artifacer gets some bonuses to use a scroll (+2 for the creation feat, and at 2nd level, can get another +4 from synergies I believe), so while it's hard at first, by second, you can have (5 ranks, +4 Synergy, +2 from the feat) 11+ stat in UMD, meaning you have at worst, a 50% chance of activating a 1st Level Scroll, and it gets better from there.
But, you could always give him an additional bonuses with personaly crafted scrolls (Like the +2 for having activated it before if he crafted it) or assume that since he crafted it, he still qualifies as having the appropriate spell.