[Calabresi]

pawn Код:

COMMAND:unbanip(playerid, params[])
{
    new ip[16];
    if(sscanf(params, "s[16]", ip)) return SendClientMessage(playerid, -1, "USAGE: /unbanip [ip]");
    new string[256];
    format(string, sizeof string, "unbanip %s", ip);
    SendRconCommand(string);
    return 1;
}

There you are. You also need sscanf to make that code working.