[Ash.]

pawn Код:

CMD:play(playerid, params[])
{
     #pragma unused params
     if(!IsPlayerInRangeOfPoint(playerid, 25.0, X, Y, Z)) return SendClientMessage(playerid, COLOUR_RED, "You are not near the beach.");
     PlayAudioStreamForPlayer(playerid, YOUR_STREAM_URL);
     return 1;
}

Please read the wiki and other tutorials about command processing, especially if you have trouble doing things like that. They are the very basics and you should really go to know at least the basics if you're (planning on) running a server.