Romark, a simple set works best. Suggestions:-
1) Keep it simple, e.g. French can move OR fire
2) Players get limited ammo, e.g. D 10 rounds (represent with marbles & hand one in each time you shoot)
3) Put some vignettes on the table, e.g. some dead Russians left over from Boradino (Flintlouge undead Russians are ideal for this. Players can always spend a move looking for ammunition on the bodies.
4) Add some things to annoy the French player(s), e.g. a pack of ravenous wolves rushing out of that nearby wood OR poorly armed peasants from that hamlet.
5) pursuing cossacks (arriving on table after a delay)
6) A battery of Russian artillery trying to blow up the bridge before the French can cross (choose an aim point then throw some deviation dice.
7) sections of ice on the river, it might hold your weight or the artillery might hit the bit of ice you are on, or the next bit you wanted to cross onto.

French sappers (vignette) preparing to blow the bridge (say a 10% chance move one, 20% move two, etc.)