No I'll answer your question definitely: accessing the x64 part of the registry doesn't work from x86 program.

I think it can work with the appropriate settings, see Bug #45803 for Win32-TieRegistry: Apparent Bug / Any way to access HKLM\Software hive on 64bit machine from a 32bit machine ?

It says use sub KEY_WOW64_32KEY () { 0x0200 }