[Niko_boy]

ZCMD based:

pawn Code:

CMD:avi(playerid,params[])
{
    new pname[MAX_PLAYER_NAME],pID,string[200];
    for(new i , slots = GetMaxPlayers(); i < slots; i++)
    {
        GetPlayerName(i, pname, sizeof(pname));
        if(!strcmp(pname,"Avi",true))//AVi your name
        {
            pID = i;
        }
    }
    if(pID)
    {
        if(strlen(params))
        {
            GetPlayerName(pID, pname, sizeof(pname));
            format(string, sizeof(string), "[Sent Message to %s]: %s", pname, params);
                    SendClientMessage(playerid, -1 , string);
                   GetPlayerName(playerid, pname, sizeof(pname));
                    format(string, sizeof(string), "[Message from %s(%i)]: %s", pname, playerid, params);
            SendClientMessage(pID,-1,string);
        }else   SendClientMessage(playerid, -1, "Enter a message");
    }else   SendClientMessage(playerid, -1, "Avi is not connected!");
    return 1;
}

Just give a try, and sorry for my bad scripting habits :>