I believe I've found a solution to this.
I created a text file on the Pi named "SyncTime.ps1", and put the text of the command I want to run in it "w32tm /resync /force".
Then I ran this script in PowerShell so that it would create a scheduled task that would sync the time on start up.
schtasks /Create /SC ONSTART /TN TimeSync /TR c:\SyncTime.ps1
There is a small delay when the Pi starts up before it syncs, but it is on the order of <10 seconds. This should be sufficient for what I need at the moment.
I decided it was a permissions issue with the user context that the application was running under. I was trying to find a way to assign the SeSystemtimePrivilege to the DefaultAccount, but didn't see any way to do that. I think the scheduled task runs under a different context.
BTW - DO NOT put the DefaultAccount in the Administrators group unless you want to end up re-flashing the microSD card.