Вот сделал по своему!
mesh_lib$=CurrentDir()+"MESH\"
mesh_dir$=ReadDir(mesh_lib$)
lib_fele$=WriteFile("LIB\main.txt")
Repeat
mesh_file$=NextFile(mesh_dir$)
If mesh_file$="" Then Exit
If FileType(mesh_lib$+""+mesh_file$) = 1 Then
meshb3d$=Right$(mesh_file$,4)
mesh3ds$=Right$(mesh_file$,4)
If meshb3d$=".b3d" Or mesh3ds$=".3ds"
Print "File:" + mesh_file$
WriteLine(lib_fele$,mesh_file$)
EndIf
EndIf
Forever
CloseDir mesh_dir$