If your target is starting an emulator or copying that disk image to a certain location, I can try to automatize this. Classic99 is working more or less. I still don't like having the filename hardcoded to Web99 there but there are certain ascii characters used for TI Files that are not allowed as characters for PC Filenames and I didn't dare to ask Tursi yet about the proper mapping, he was quite busy lately on Backup/Server Data losses.
Basically Classic99 expects all illegal characters to be remapped to '~' on the disk. When the TI requests a file with an illegal character, it will transparently map it through to '~' for the actual disk access. The actual list of characters is "?/<>*| (double quote, question mark, forward slash, less than, greater than, asterisk and pipe). Backslash and colon ( \: ) are also illegal characters on the PC filesystem, but Classic99 does not yet remap these because it uses them as PC path names. However, this is going to change very soon, so I would recommend you include them in the remapping list (just be aware they won't work yet). Fortunately these are rare in TI filenames.
This differs (a lot) from the way V9T9 did it, but this is for three reasons. The first is that V9T9 was written for DOS, which was much more restrictive on filenames than modern Windows. NTFS supports nearly all the characters that the TI did, as well as the full filename length -- even FAT32 does. The second is that the high ASCII characters V9T9 used in place of those illegal characters are difficult to work with on Windows, and a goal of Classic99's FIAD system was to enable full use of Windows as the file manager. And the final reason is that Classic99 does not natively support the filename inside the file (there's limited support for it in V9T9 files, but it's not 100% compatible) -- again for the same reason that Windows needs to work as the file manager.
Edited by Tursi, Mon Dec 28, 2015 6:16 PM.