H> Party Drop Script

[Rizz]

Hello, I found a party drop script made by llchrisll, however I need a help to modify this script only give the drop share within screen 15x15 area so the party member outside the screen can't leech. 

Moreover, this scripts uses general drop chance, would you like to help me changing this into specific one?
For example:
OnInit:
setarray .drop_id[0],15378, // Lava Leather Armor - 2% chance
                     15379, // Lava Leather Suit - 5%
                     15380, // Lava Leather Robe - 2%

 

//==================================================
// Party Drop Script
//==================================================
mag_dun03,0,0,0	script	#MagmaF3_Drop	-1,{

OnMagma3MobDead:
if(getcharid(1)) {
    getpartymember getcharid(1),1;
    getpartymember getcharid(1),2;
    
    for ( .@p = 0; .@p < $@partymembercount; .@p++)
        if(attachrid($@partymemberaid[.@p],$@partymembercid[.@p]) == 1) {
            if(strcharinfo(3) != strnpcinfo(4)) continue;
            if(rand(1,10000) >= (10000 - .chance)) 
                getitem .drop_id[rand(getarraysize(.drop_id))],1;
        }

} else {
	if(rand(1,10000) >= (10000 - .chance)) 
		getitem .drop_id[rand(getarraysize(.drop_id))],1;
}
end;

OnInit:
setarray .drop_id[0],15378, // Lava Leather Armor
					 15379, // Lava Leather Suit
					 15380, // Lava Leather Robe
					 20935, // Lava Leather Manteau
					 20936, // Lava Leather Muffler
					 20937, // Lava Leather Hood
					 22199, // Lava Leather Boots
					 22200, // Lava Leather Shoes
					 22201; // Lava Leather Sandals
// ==== Drop Settings ====
// Multiply the Drop Chance below with the Server Drop Chance for Equipment
// 1 = Yes
// 0 = No
.battleconf_drop = 0;
// General Drop Chance
.drop = 50; // 50 = 0.5%
// Calculation
.chance = .drop * ( (.battleconf_drop)?( (getbattleflag("item_rate_equip")%100 > 0)? (getbattleflag("item_rate_equip")/100):1):1);
end;
}