sikuli to work on backgroud task

Hi,I am using selenium webdriver and sikuli integrated with it. so i have to code in java in eclipse IDE. I have a scenario where i have to test many cases, simultaneous i should some other work. But with sikuli i Found that the screen should be foreground, it cannot perform the tasks if its has to interact with backgroud.
example these few lines are part of code where sikuli selects a screen and finds image and cliks
                    Screen s=new Screen();
       s.exists("img/openpopup.jpg", 0);
      s.click("img/open.jpg", 0);
       s.click("img/ok1.png",0);
here if Iam working on some other screen parallel and sikuli assumes my current screen which I am running as the scenari and tries to find the image on my current screen. which throws an error because it cant find the image.

this is what I need is there any way so that sikuli would check for even the invisible screen (or back ground screen) and then check for image? why because i dont want to stay computer idle to just run it for automating sikuli but also I need to simultaneously work on it so that if you have too many test cases you wont loose time and in java I can use a log that I can check at the end of the test code to see if any failures...

please help me guys ... I am new to sikuli i dont know how to make it work on the back ground screens
thank you