Public Sub ListDirsAndSubdirs()
startdir = "c:\"' replace with starting directory
On Error GoTo NEXT_STEP
' find all directories and subdirs from a starting point
current = 0
dircount = 0
currentdir = startdir
While current <= dircount
    subdirect = Dir(currentdir, vbDirectory + vbHidden)
    While subdirect <> ""
        If subdirect <> "." And subdirect <> ".." Then
            If (GetAttr(currentdir & subdirect) And vbDirectory) = vbDirectory Then
                dircount = dircount + 1
                ReDim Preserve aryFoundDirectories(dircount)
                aryFoundDirectories(dircount) = currentdir & subdirect & "\"
            End If
        End If
        subdirect = Dir
    Wend
    current = current + 1
    currentdir = aryFoundDirectories(current)
Wend
dircount = dircount + 1
ReDim Preserve aryFoundDirectories(dircount)
aryFoundDirectories(dircount) = startdir
NEXT_STEP:
' find all files with matching extensions
For i = 1 To UBound(aryFoundDirectories())
    Selection.InsertAfter Text:=aryFoundDirectories(i) & Chr(13)
    Selection.START = Selection.End
Next
End Sub