first: the fog is not ur problem, viewdistance is.
this can be controlled by server via setting it in objectspawns.con
this will also prevent any of these " easy fix hackers" from gaining some kind of advantage by removing fog, since server will not show vehicles/enemy until set distance is reached. and if u need to remove fog to see them at that time, have ur eyes examined.
... as for not talking about hacking , lol, the stuff that could be done client side to cheat is known and watched , also, the veterans of bf1942 and its mods will prevail any of these cheats or identifiy them easy.
so if u want to cheat , go ahead, fumble with ur files, u will be smoked or banned.
but i suggest u use ur talent for something productive.
as to the question:
the command for objectspawns.con servermap is
game.setviewdistance xxx (average value hee is 500[m])
this will show enemy sooner or further, defined by server, fog or not ...
removing fog is only possible clientside and senseless because it requires more resources since the map graphics are calculated further out, and only those
.