I've been using an .xml map editor I quickly roughed up quite a bit recently (I find it's useful when copying and pasting repeated patterns in particular), so I've cleaned it up for anyone else to use if they want to as well. (In particular, it should work in pretty much any spreadsheet software (not just Excel) since it's an .xml, meaning that Mac / Linux / etc. can use it as well which given they don't have a map editor may well come in handy.)
> Input area is the grey grid; it's 100 x 100, which should be fine since AVWW really doesn't like rooms that are any larger.
> Output area is the yellow area; it's pretty much a select-the-area-and-copy-it-into-a-.txt-editor affair, so fairly straightforward.
> The legend doesn't includes the Special entries since they're not used, but everything else is there. (This is both for those who can't see what symbols are used due to not being in Windows, and as a reminder, though it's important to note that capitilisation is important; it's worth sticking CapsLock on when using the sheet.)
> The formulae are set up so that if a cell does not contain anything but both the column it is in and the row that it is in has something, it'll treat it as an "." rather than a blank; this is mainly so that it maintains a rectangular shape for the output to avoid a horrible mess when the game tries to translate it and can't, but also means you don't need to go around filling in all the surrounding area with "."s.
> Nothing's locked; the calculations have been hidden, but if you want to pull the columns / rows open back into view and have a fiddle with it, go ahead.
Anyway, the sheet's attached at the bottom for those that want it.