I have a pre-defined csv template. The header row begins on row 5.
Prior to this I have a date value in cell B2.
How do I update this cell value in SSIS?
CSV would not have the cell ordinals you have specified. This happens only when you try to open your file in Excel. In order to emulate this, you will have to read the content of 2nd row and 2nd column.
This can be done using a Script Task in SSIS.