Yes, you can edit the list in Notepad and save it to add a batch of words to your custom Scrivener dictionary.
You don’t need to run Scrivener from Dropbox to sync the wordlist. It’s a little more complicated than the usual method, since Dropbox syncs based on the contents of the “Dropbox” folder on your drive; you need to set it up with symbolic links. There’s an article detailing this here.
I think this will only work transparently as long as the words you add don’t contain accented or otherwise special characters. Scrivener does some sort of encoding on those characters, so they won’t look the same when you explore the wordlist via the user interface as they look on Notepad/Notepad++.
This is my case since a write mostly in Spanish, so overwriting or syncing the wordlist file is my path of choice.
I use DropBox as well, but decided to include Cubby in cases like this because it allows you to define any of your folders as shared. Several tools save config files on the AppData folder, so it has been a life saviour for me to use them all on different computers.
OMG, NOW I get what you mean by “processors”: not machines, but word processors. What you really need is to populate Scrivener dictionary from Microsoft Word…
Sorry, I misunderstood your need. My previous advice was in order to use the same dictionary on two different Scrivener installations.
As per your real need, I have no idea how to get that data from Word XP. I did a quick Google search and found this tutorial, which is for more recent versions of Word, but the process may be may be similar for yours: