It can be done with a table. I did a similar thing for our users that are running my web software on a box that is so restrictive that they cannot even access file manager! There are legacy functions that can be run to create reports on the computer that could not be accessed. This NT web page allows them to navigate the drive, select a file which is then copied into a folder beneath the web root to be zipped and transferred off the web computer to their local computer.
It worked pretty well and did a reasonable job of mimicing the file manager functionality. Each column in the table was the next folder level. A similar approach should work for trees, but don't forget to span columns with each tree entry or the table will get too wide to handle..
Rob