正規表現でgオプションをつけた場合の後方参照にはRegEx.exec()を利用する

gistfile1.js

var body = 'foo target1 target2 bar target3 hoge';
var re = /¥s(target(¥d))¥s/g;
var results = [];
while (results = re.exec(body)) {
	console.log(results);
	// ['foo target1 target2 bar target3 hoge', 'target1', '1']
	// ['foo target1 target2 bar target3 hoge', 'target2', '2']
	// ['foo target1 target2 bar target3 hoge', 'target3', '3']
};