You are running into a problem here.
The french employed various different skirmishing drills during the war.
Some of them use their own horn signals, but we unfortunatly no longer have any sources available to tell what they sounded like. We only have a list of signals, but the notes are lost.
Some others we have a few remaining tracks, but not much by any means. I.e. useless for the game.
The Skirmishing drill employed by the corp under command of Davout:
7e, 13e, 15e & 33e régiment d'infanterie légère
12e, 17e, 21e, 25e, 30e, 33e, 48e, 57e, 61e, 85e, 108e & 111e régiment d'infanterie de ligne
used commonly known songs/signals as horn and drum signals. Note above, the 85e! which is in the game employed this skirmishing rill. Technically this drill is from 1811, so kinda late for the game, but I guess that does not matter much.
Movement Drums Horns
Déployement La Breloque Déployement
Ralliement Aux Drapeaux Ralliement
Retraite Retraite Retraite
Marcher à droite La Grenadière Marche à droite
Marche à gauche Les trois coups de charge Marche à gauche
La Charge La Charge La Charge
Marche lente Pas Ordinaire Pas Ordinaire
Marche précipitée La Charge avec roulement Marche précipitée
S'arrêter La Messe La Messe
I am sure you will be able to find sheet music or tracks for some of these. You can probably look up the sheet music for most of them, since I am somehow 100% sure that they are still avaiable, but I don't know where exactly to start looking as I am not really intersted in light infantry stuff for bugles.