Not sure what an attachment control is, but are you talking about an attachment FIELD?
If so, you treat the field as a recordset. (a recset in a recset)
Code:
Public Sub OpenAttach()
Dim att
Dim rst
Dim i As Integer
Set rst = CurrentDb.OpenRecordset("qsAtt")
Set att = rst.Fields("attachFld").Value 'it a recordset
With att
While Not .EOF
'Debug.Print att.Fields(2).Name, att.Fields(2).Value
.Fields("FileData").SaveToFile "\\myserver\myfolder\rst.xlsx"
.MoveNext
Wend
End With
Set rst = Nothing
Set att = Nothing
End Sub