Ralph or rather Ney - explained it very well, a battalion column has usually a frontage of one company or peloton one behind each other, such was the understanding when the authors spoke of a battalion column.

I also would agree that a colonnes serrées par regiment, is one battalion column (of peloton width) behind each ohter.

No other colonnes are described in the regulations, how would you form a regiment in a column of battalion width? You would first have to deploy each battalion in line and then form then into a column.

The problem with the colonne d'attaque (my all time favourite) and why it came out of fashion was - that on the approach march - usually columns of peloton width were used, so to form a colonne d'attaque, those would first have to form a line and then again a column, akward.

By that - instead they just formed either

1. a battlion column
2. a battlion column by divisions with to the left, see the link Ralph supplied.

HK