Looking for guidance to see if SharePoint lists can handle this logic...
Where you have two lists, list1 is the detailed record and list2 are records associated with an entry in list1
SiebelID Opportunity Name Original B&P Orig Date Approved B&P Last Update
SIebeID ReqType Date Approver Status Amount
So the first time a request is placed with a SIEBEL ID and approved in LIST2 it creates a record in LIST1 and the original B&P and Approved B&P are set to amount from LIST2
Each time a subsequent approved record is added to LIST2 corresponding LIST1 is updated adding Amount to Approved B&P