Couple questions... How did the .docx get onto your iPad in the first place? What do you want to do when you say "upload"? Would emailing it suffice? Do you have an app that reads or otherwise handles .docx? If so, maybe it has a "Share" button.
Google just made its QuickOffice app (
http://googleenterprise.blogspot.co...r-everyone.html?source=email_rt_mc_body&app=n) free... maybe it can handle the sharing for you.
There are plenty of apps including GoodReader and Dropbox that let you set up a folder system for themselves the old-fashioned way.
Beyond that, Apple decided after much study that the folder-and-file system was causing problems for many users. Though you and I have no issue with it and are entirely familiar with the concept from familiarity with legacy systems like OS X/Unix, Linux, Windows and even DOS (v. 2 and later), I can see their point: one family member (really not a tech tard) gets hung up on it on occasion ("I don't want the spreadsheet on my desktop, I want it in Excel!"), and I had to help a friend unravel her PC once after she broke it utterly by putting all her documents in the Windows system folder, which for some reason made sense to her because it's a Windows machine, right? ...So Apple decided to let apps manage their own files so the user doesn't have to. Your issue may boil down to not having an app that does stuff with .docx files, then.
Sorry you're frustrated, and I've been there too.