Please excuse the use of cloned names for the French. It appears that Petit was a brigade CO and also was in charge of a regiment with the traditional two battalions. Also, it appears that all French regimental commanders commanded both battalions (within each regiment). I did my online searches, but got nada but regimental commanders, not a battalion leader to be found, or second in command...so help here would be greatly appreciated. I know books are more definitive in this regard, apologizes, but I've got limited resources here in backwoods Arkansas, plus my old eyes don't do well with book learnin' anymore.
Maybe you manage to access this site from Arkansas. I haven't checked Waterloo's but you should have 127 meg of sheer joy:
http://theminiaturespage.com/boards/msg.mv?id=253661 Go to blue highlited TMP link then prompted to a pdf file, all zipped. Hope this helps.
Edit: I went through Waterloo's and it doesn't go below Brigade. However this one should help:
http://waterloo-1815.forumactif.com/t33 ... -1er-corps
[Army of the North 1st Corp OOB]; down to the Battalion commander from the 3rd post on. In French, if you need it I can translate it all.