Option Explicit
Sub Test()
Dim strPath As String
Dim strFile As String
strPath = "X:\Verzeichnis\Unterverzeichnis"
If Right$(strPath, 1) <> "\" _
Then strPath = strPath & "\"
strFile = Dir$(strPath)
Do While strFile <> ""
If InStr(strFile, "337") And GetExtension(strFile) = "pdf" Then
Debug.Print "PDF:", strFile
ElseIf InStr(strFile, "Foto") And GetExtension(strFile) = "jpg" Then
Debug.Print "FOTO:", strFile
ElseIf GetExtension(strFile) Like "xls*" Then
Debug.Print "EXCEL:", strFile
End If
strFile = Dir$()
Loop
End Sub
Function GetExtension(File As String) As String
Dim i As Long
i = InStrRev(File, ".")
If i Then GetExtension = Right$(File, Len(File) - i)
End Function