Airport Express file server, accessible from an iOS device

I often travel to places where I need to be able to add Word and Excel files to my iPad from a USB thumb drive, so I thought of the following workaround:

1) Get an Airport Express and a USB thumb drive

2) Copy data file to USB thumb drive and plug the drive into the Airport Express

2) Create a dedicated WiFi network

3) Upload some sort of an app to the iPad allowing me to access the thumb drive from the Word and Excel apps

4) Access the data file through the WiFi network the same way I would do if it was on Dropbox or some other file hosting service

So the big question is if "some sort of an app" like this exists. Has anyone heard of a locally-hosted Dropbox-like solution?

Yes, I know that's an old predicament and I know that the iPad has no USB port and the CCK doesn't help with documents. The files have to come either from a USB flash drive or an SD card. I have no access to another computer where I can install iTunes and there is no Internet access whatsoever.

Cheers!