@mruPRQUJ hi,
to create a list of files no lisp is need. you can google for applications that do that
or you can just use command prompt old and good DIR (directory) command to do it.
example:
c:\project01\dwg> dir *.dwg /b >michael.txt
this command will create (in 1 sec 🤣) "michael.txt" file containing a list of all dwg files in current folder.
[if you like, it can be called from any lisp program with (startapp) function]
the > greater then character redirect the output to file (instead of the console\screen)
the /b is to eliminate all info except for the files name.
enjoy
Moshe