How to hide source filename and change BAR_FILENAME_LENGTH, BAR_BEAM_RATIO ratio in windows

Neither BAR_FILENAME_LENGTH=7 ffmpeg-bar -i in.mp4 output.mp4
nor BAR_BAR_SIZE_RATIO=0.5 ffmpeg-bar -i in.mp4 output.mp4 are working because it says "BAR_BAR_SIZE_RATIO' is not recognized as an internal or external command" and also I couldn't find any file or named BAR_FILENAME_LENGTH or BAR_BAR_SIZE_RATIO so that I could have set new environment variables for them. 