[Stinged]

pawn Код:

CMD:suspect(playerid, params[])
{
    new id,discription;
    if(sscanf(params,"us"id,discription)) SendClientMessage(playerid, -1, "USAGE: /su(spect) [id/name] [discription]");
    else if(id == INVALID_PLAYER_ID) SendClientMessage(playerid, -1, "ERROR: Player is not connected.");
    else
    {
        // Do what you want here.
    }
    return 1;
}

CMD:su(playerid, params[])
{
    return command_suspect(playerid, params[]); // Now /su will be the same as /suspect
}

That's pretty much it.
You need sscanf for this.