以下のように、現在の行の前の行の値を取得したい(Crystal Report 2008):
+------------+-----------------+----------+------------+----------------+
| Date | PreviousBalance | Loan | Collection | CurrentBalance |
+============+=================+==========+============+================|
| 14/02/2012 | 00.00 | 10000.00 | 00.00 | 10,000.00 |
| 15/02/2012 | 10,000.00 | 00.00 | 500.00 | 9,500.00 |
| 16/02/2012 | 9,500.00 | 00.00 | 500.00 | 9,000.00 |
| 18/02/2012 | 9,000.00 | 5,000.00 | 00.00 | 14,000.00 |
+------------+-----------------+----------+------------+----------------+