String arh = ... 
                Process proc = Runtime.getRuntime().exec(arh);
                String line;
                BufferedReader input =
                         new  BufferedReader
                        ( new  InputStreamReader(proc.getInputStream(),
                        "Cp866"));
                 while  ((line = input.readLine()) !=  null ) {
                    System.out.println(line);                     
                }

        double  d =  0 ;
        if  (line.indexOf("Ваши данные:")> 0 ) {
            d =  Double .parseDouble(line.substring(line.indexOf("Ваши данные:"), line.length()));
       }