HTML Import 2 Hierchy Structure

Hello all,
I’ve searched quite a bit and hit up the IRC but can’t seem to get anywhere. I have a html site with about 3,500 pages. I’m trying to convert it to a WordPress site. I managed to import the pages successfully, however it always imports them as mass pages without the origional structure. I’m hoping there’s a way to do this as I spent relentless hours getting the structure set.

Currently the hierchy is fairly simple

domainname/Topic-Menu-Page(with multiple links)/Topic-Menu-SubCatagory(with multiple links)/Posts-Page

ex: Cellular (Links For different Carriers)
Carrier (links for different Brands)
Brand (links for different models)
Model (final page with info postings)
so it would layout – cellular/sprint/motorola/XT910.html

Any Ideas? Can it be done with setting permalinks first before Importing?
Any clue how I would do that?
Thank you so much in advance (hate to have to copy and paste +3K pages)