Hi Yoshiyuki,

If it helps, the Legacy Converter is actually a plugin these days, although it's essentially the same code as the standalone but just delivered as an sdlplugin, so you could adapt the code for this to be part of your  batch task process.  So you would add the conversion and export batch tasks in Studio to the end of your project creation process and then create an import TTX batch task to update your projects with the translated TTX at the end of it.

The source code is here:

https://github.com/sdl/Sdl-Community/tree/master/Legacy%20Converter

Be aware however that this process is source -> sdlxliff -> ttx which means you cannot recreate the original file format from this ttx.  You will just have a file that you can handle in a ttx compliant tool.  This article will give you an idea how it worked in standalone mode before it became an sdlplugin:

https://multifarious.filkin.com/2013/07/01/legacy_converter/

Regards

Paul