I've got a base transactional table with a numeric DocType field (20=GRPO, 59=Goods Receipt, 60=Goods Issue). Depending on what value is in that field, I'd like to associate the corresponding DocEntry field with a different table (OPDN, OIGN, OIGE respectively) without generating a synthetic key or a loop. What's the best way to handle that within a load script? I've got a common ItemCode field across all of the tables, as well as a lot# field. The alias is primarily so that I can track the item and lot# accurately.