I think you might be confusing two things.
If you are talking about a weapon mod (editting weapons' speed, power, damage, ...) you just need to do the command:
/loadwep <weaponfile>
If you are talking about a mod that changes the graphical aspect of soldat (appearance of your soldat character, graphics of the weapons, ...), there is no way to force everyone to use the same graphical mod as you have.