I sell through a distributor who, on his turn, sells to wholesalers (mainly, but might be also points of sale). Every month I receive from the distributor a list of the sales with the "real" customer (wholesalers/pos) purchasing details but I will just issue one invoice, for the distributor. Anyway I need to import the details to know who is buying, how much and so on (for statistical and geographical analysis). So, my actual customer is the distributor, but I need to track his sales too! How can I manage such a hierarchy in OpenErp?