What I want to do is more complex than selecting a file from a list of files. I will start in a directory, then I want to change to the most recently modified directory. I then want to repeat that process in a sub-directory, and then, inside of that, I want to select the most recently modified excel file and open it.
What is the best approach to do this?
What objects / methods should I be looking into?
The simplest function is
FileDateTime(pathname)
where pathname can be a directory for folder.
Alternatively, you can use the FileSystemObject object, DateLastModified property:
Dim fileModDate As String
Set fs = CreateObject("Scripting.FileSystemObject")
Set f = fs.GetFile(<filenamestringhere>)
fileModDate = f.DateLastModified
All of the above can be explored in VBA help.
来源：https://stackoverflow.com/questions/6656023/vba-how-to-get-the-last-modified-file-or-folder-in-a-directory-in-excel-2010