Using that code, you would place this line at line 56
AirraidPlayerMsg = _rndLoc; publicVariable "AirraidPlayerMsg";
But in your player_message.sqf script there is no code to determine if the player is inside of that city (_rndloc)
So you would want to replace your player_message.sqf code block
if(_city != _lastCity) then {
with something that compares if the player is within that city. something like this
//_nearestcity will be a coordinates of the closest city to a player
_nearestCity =
nearestLocation [
getPos player, "nameCity"];
//_meters will be distance player to the above located nearest city. You may have to translate _nearestcity into actual worldspace though
_meters=player
distance _nearestcity
//now, is player close enough to city to get messages?
if (_meters < 500) then {
or do something like this ..
As for playing the sound from in-game .. yes
I think you can use this code
https://community.bistudio.com/wiki/playMusic but to check, go into your editor and create the air raid sound to play on a trigger and then see what code is produced.