[Kush]

Your using ZCMD, not 'CMD: style commands'.

Alright, so if I understand you clearly, you'd like a command, in which the text you input would then Send a Message to everyone connected on the server. I'll be doing it in ZCMD and sscanf.

pawn Код:

CMD:sayhi(playerid, params[])
{
        new Str[128];
        if(sscanf(params, "s[128]", params)) return SendClientMessage(playerid, COLOR_GREY, "USAGE: /sayhi [message]");
        format(Str, sizeof(Str), "%s", params);
        SendClientMessageToAll(COLOR_WHITE, Str);
    }
    return 1;
}