VAICOM PRO uses a plugin to interact with DCS, however the data it uses may not be made available for use outside its own profile; That would be up to its author.
I'm not personally aware of any VoiceAttack plugins for getting general DCS data, though they may exist.
There is a project called DCS-BIOS which is intended to interface with physical cockpit controls, however you may be able to adapt that for use with a VoiceAttack plugin (license permitting).
Keep in mind that most games and other applications use their own proprietary methods for storing and handling data, so there is no universal solution to get internal data from them. Even DCS internally doesn't adhere to any real standard when it comes to the cockpit control data for individual aircraft.