The example doa061engsub likely refers to commercially copyrighted content. This guide is for personal, legal file conversion (e.g., home videos, public domain media, or content you own a license to). Do not circumvent DRM or distribute converted files without permission.

After conversion, check:

mkvmerge -o DOA061_final.mkv \
    --language 0:eng \
    --track-name 0:"English Subtitles" \
    DOA061.mkv \
    DOA061ENGSUB_corrected.ass

Result: DOA061_final.mkv contains the original video + a properly timed English subtitle track that supports unlimited hours.