I'm not at a computer to check but isn't NewItemCode field available to import into? I don't believe it's set as Read Only in the dictionary. Assuming you have the right Operation value set for Renumber, and both Starting and Ending ItemCode set, the business object should allow you to set the NewItemCode on the import - @JeffSchwenk may have some incites (pun intended, cr to @JeffSchwenk) into this as he has done a fair number of these I think.