Desktop Plus will transfer some AVI files and editing the tags may help a bit, but it won't "folderize" them. To do that you would have to push them using pyTiVo and custom metadata files.
If you want to go to the effort of converting them to MPEG-2 files first it's possible to add TiVo metadata to them, but it's not a method that has been pursued very far. See http://www.tivocommunity.com/tivo-vb/showthread.php?t=446048 for more info if you really like a challenge.
If you want to go to the effort of converting them to MPEG-2 files first it's possible to add TiVo metadata to them, but it's not a method that has been pursued very far. See http://www.tivocommunity.com/tivo-vb/showthread.php?t=446048 for more info if you really like a challenge.