MP3 to FLAC Transcoding

I'm trying to convert MP3 to FLAC at LMS to enable some features on the player - I realize this does nothing to the sound quality but there's a reason I want to do this.

In the convert.conf file there's this which appears commented out:

# FLAC output starts here

#mp3 flc * *
# [lame] --mp3input --decode -t --silent $FILE$ - | [flac] -cs --totally-silent --compression-level-0 -

But when I put this into a custom-convert.conf file and remove the initial sign, it doesn't work, doesn't show up at all. Is this language correct?

Thanks!