You need two files if you want to add text from .msg and .ini files, one with the source language and another built the same way but with text for the destination language.
The script handle missing translations, but may require a watchful eye afterward.
Please do provide an url (and possibly code) or two, for other translation services than google one could use (as backup) as well.
See the script for one code example as of now.
It would also be very convenient if one could add support for more file formats... perhaps system specific files?!
OS/2 system files often need to be disassembled before one can extract the useful stuff.
Do explore and present command line resource (de)compilers along with other tools and scripts to extract text.
The translation team have the knowledge and it would be most useful if they'd share it and we could include such info into a tool so not everyone need to be a rocket scientist, on top of everything else, but can focus on writing good translations.