A new action is now available in the Wow64 plugin: Wow64.RegistryGetAccess().
This new action emulates the function Registry.GetAccess() as provided in the Indigo Rose development products, however this version obviously allows to work on the 64-bit registry view from a 32-bit application.
The version 1.0.4.0 of the Wow64 actions plugin is available for download for both Lua 5.0 and Lua 5.1.