How to burn in (hardcoded ?) PGS subtitle ?

[reko]

Hi,

I have many MTS/AVCHD files from my handycam.
Each MTS has PGS sub stream (contains date taken) where if I play in MPCHC, I can turn it on/off.
I want to edit those MTS file in Adobe Premiere together with the date taken, but Premiere can't read the PGS sub.

I have tried to put one MTS file to Handbrake,
On "Subtitle" tab of Handbrake, I add "new track", choose the PGS tream, tick the "burn-in" mode....
and the transcoded mp4 video file has that "burn in" of the date taken.

Happy it work, so I import all those MTS files to Handbrake by choosing a folder.
After waiting for a long time, finally Handbrake finish reading all those imported MTS files.
But to my disappointment, I can't do it in batch encoding with Handbrake.
Handbrake's pop up window told me that regarding audio and subtitle it would be reset to the default to the next file.

Since there are hundreds of MTS files which I need to "burn in" each of their PGS sub,
adding it to Handbrake's queue one by one is tedious for me.

My question, is there any free program which can do similar like Handbrake but also can do the batch encoding ?
Is there any other way to do what I want ? Via ffmpeg maybe ?

Any kind of help would be greatly appreciated.
Thank you in advanced.

------------------------------------------------------------------------------------------------------------
EDIT:

Please ignore my question,
I finally found out on how to do it from this link.

for %%g in ("*.MTS") do ffmpeg -i %%g -deinterlace -s "1280x720" -crf 23 -c:a aac -b:a 96k -filter_complex "[0:v][0:s]overlay[v]" -map "[v]" -map 0:a %%~ng_test.mp4
pause

Thank you.