3DS Max Script for Game Project

I'm doing an engine transfer from R3Engine to Unity of an old MMORPG, when our community was thriving we made many tools to access the files and modify them, unfortunately, the game is old and the community has died out, and I want to preserve the game, porting it to Unity will allow me to keep developing features for it, because of this, I need a script to open and export the game files in the correct format to Blender/Unity. I already have a script for it, but it doesn't open/export correctly the bones and the animation.