Excel 2007 : Creating dynamic formulas based on selections in one sheet with data from another

[filbil]

We have a workbook tied to an Oracle database. Within the workbook we have a worksheet (1) with standard formulas built in. We have data coming from an Oracle table that we use to edit new entered data on worksheet 1 that is stored in a separate worksheet (2) contained in the same workbook. The data in worksheet 1 is based on a project id identified in a column header. The project id selection would trigger the use of data in worksheet 2 that needs to be included in the formulas in worksheet 1. So for example worksheet 1 contains a formula [=sum(d1:d4)]. We need to adjust the formula to include cell values from worksheet 2 tied to the project selected in worksheet 1. So the formula then would need to be revised to reflect =sum(d1:d4) + ws2.M5 + ws2.N5 where ws2.M5 and ws2.N5 are from the other worksheet. The project would be identified by the row and the values would be identified by the column in worksheet 2.