I've read the pub, and from my interpretation, no unfortunately.
You can't claim it as a "higher education" expense, because the student doesn't qualify for such expenses yet. They won't qualify until they are
-Enrolled in a course of study as a full time student at a qualified institution that will lead to a degree or certification.
As a high school student, there's no way they are a "full time student" in that "course of study" that will lead to the degree or certification.
Additionally, the purchase of a computer is not a requirement for high school. It's a requirement for a college course the student does not yet qualify for anyone to claim such expenses on.
IRS Publication 970 at https://www.irs.gov/pub/irs-pdf/p970.pdf page 50 starts the QTP/529 section. Second column titled "Qualified Education Expenses" That first paragraph starts:
Generally, these are expenses required for the enrollment or attendance of the designated beneficiary at an eligible educational institution. For purposes of QTPs, the expenses can be either qualified higher education expenses
You don't yet qualify to claim higher education expenses since there's no way they are a full time student at any college.
or, for amounts paid from distributions made after December 31, 2017, for qualified elementary and secondary educa-tion expenses.
The computer is not required for his elementary or secondary education.
You also want to be careful about using education credits before they are enrolled in college as a full time student. There are many tax credits you qualify for that you can only take for four years. While those credits have a maximum amount for each year, the credits are based on and limited to your out of pocket qualified education expenses. So if you use a credit in a year when say, your out of pocket expense is only $100 on a credit that has a max of $2000, then you only get $100 credit and that's flat out it. Then in the last year of college when you have that $2000 of OOP expense and "need" that credit, you can't use it, because you wasted it for a measly $100 in that first year.