Problem regarding placing movieclip randomly on background

Hi All,

I am facing problem regarding placing movieclip randomly. I have a huge background , some movieclips are placed over there . and background is panning horizontally. and what i have to do is if any movieclip is outside the stage , it should be place somewhere else on the background except on stage area. so that when we go back we can see that clip somewhere else on the background .

Thanks and Regards ,