[guffer]

сделал так:

var fso = new ActiveXObject("Scripting.FileSystemObject");
	var ts = fso.OpenTextFile("logs/"+ rtrim(xmlUMKbaseconfig.documentElement.getElementsByTagName('umk_name')[0].text) + ".txt");
	var result = new Array;
	var i = 0;
	while (!ts.AtEndOfStream)
    {
		var r = ts.ReadLine();
		var x = /\d+(?=\%)/.exec(r);
		result[i] = x;
		i++;
    }
	ts.Close();