This is fairly simple with a script associated with a rule to identify the message sender (or to process all incoming messages) . The code assumes that the target folder exists and overwrites any existing file of the same name in the target folder.
Sub SaveAttachment(olItem As MailItem)
'An Outlook macro by Graham Mayor
Dim olAttach As Attachment
Dim strFname As String
Dim j As Long
Const strSaveFldr As String = "D:\Test\" 'folder must exist
On Error GoTo lbl_Exit
If olItem.Attachments.Count > 0 Then
For j = 1 to olItem.Attachments.Count
Set olAttach = olItem.Attachments(j)
If UCase(olAttach.fileName) = "ABC.XLS" Then
strFname = olAttach.fileName
olAttach.SaveAsFile strSaveFldr & strFname
Exit For
End If
Next j
olItem.Save
End If
lbl_Exit:
Set olAttach = Nothing
Set olItem = Nothing
Exit Sub
End Sub