If you care to fix your typo for other readers, click the "Edit" button on your original post, then click "Go Advanced" and you will see where to edit the thread title.
Yes, the original file stays wherever it was, unless you elect to delete it. The new file is saved wherever saved it.
No, all the work is done by the app on your computer. You don't even need an internet connection for it to work.Great, thanks. I was just worried it would get stuck on someone's server or whatever (sorry, as you can see I'm not very literate with these things, but it's research material so I'm supposed to be a bit careful with it). Thanks again