expired domain + keeping pagerank

hey. i brought a expired domain with pr5 , the problem is that only the index.php have that pr , if i do mydomain.com/whatever/index.php the pr is 0
is there a ways to get them good pr too as the root page?

lol wayback machine
get the latest directory structure of the website
build it back the way it was, i am sure there are lots of inner pages with pr3-4-5 as well.

you can't keep the pagerank of an expired domain for long, better flip it right away...