This is a small utility tool developed with AutoLisp which import drawings files of different types in to AutoCAD and create drawing files in the folder. No matter how the directory structure is, it will still import all the files and move the original files to a sub-folder. In the upcoming videos, we will see more in importing descriptively in to AutoCAD.

AutoCAD 2018 supports these format files,

("*.ste" "*.stp" "*.step" ".dxf" "*.iges" "*.igs" "*.fbx" "*.sat" "*.ipt" "*.iam" "*.model" "*.session" "*.CATProduct" "*.dgn" "*.ij" "*.prt" "*.asm*" "*.3dm" "*.sldprt" "*.asm" "*.sldasm" "*.g" "*.x_b" "*.x_t" )

Watch how it works: 

More on this https://www.gsunitedtechnologies.com/cad/stepimport/?referer=cadforum

Import CAD format files recursively to AutoCAD - Visual Lisp