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