About advanced preloaders

Good day

how would one make this kind of preloader with AS 2


I saw alot of tutorials about preloaders but they all explain same kind of line or bar filling up preloader why not a more complex ones where for example i have 1 box that slide to the left when 20% has been loaded so that is 20% for each box 1box20% 2box20% 3box20% 4box20% 5box20% =100%

I cant find TUT for that thats why am posting this so please and thanks