miauu's Batch Save/Export OBJ/FBX/3DS/MAX as OBJ/FBX/3DS/MAX files handles batch saving and exporting inside 3ds Max. It works with selected OBJ, FBX, 3DS or MAX files and writes them out as OBJ, FBX, 3DS or MAX. Only files whose checkboxes are turned on get processed and saved as MAX files, and you can choose the 3ds Max version the MAX files are saved to. The UI can be resized.
Files can be gathered two ways. The Get Directory button selects every OBJ/FBX/3DS/MAX file in a chosen folder, and if that folder has sub-folders the script asks whether to load the files in the sub-folders as well. The Get File(s) button lets you pick files directly, with multiple selection so you can open a folder and select several at once.
The file list responds to mouse actions. Right-clicking a file name opens its folder in Windows Explorer, and middle-clicking removes that file from the list. A Show Full Path checkbox switches between the full path and the file name only, with names shown by default.