It depends. If the student was enrolled in Private/Home School for a minimum of 1 full year prior to switching to a VHSL school, then no problem. If not, then the student must be registered w/the VHSL school for a minimum of 365 days. Of course, there are a number of exceptions and other relevant rules, so I'd suggest you contact your appropriate VHSL staffer... and read sec. 28 of this
VHSL Handbook