Merge Old Html Site Permalinks Into WordPress

Hi,

I am migrating an old html website into WordPress and I need to maintain the permalink structure.

I found a plugin that adds a .htm to the end of all my pages (.htm on PAGES) as you can see I added it here for testing:

http://joshuaspoon.com/test10/test.htm

I need to figure out a way to maintain multiple folder permalink structures. Here is an example: http://joshuaspoon.com/test10/folder1/folder2 . Every time I add a forward slash into the WordPress page permalink structure WordPress removes it.

I need a solution for this.

Thanks for your time!

Joshua