Presently with an excel DataSink it's not possible to define column headers to the Excel file you're creating.
This can present challenges, as it did for me, this combined with the fact that you can't append to an existing Excel file meant all had to be done via CSV file go create the content you wanted, then read the CSV file back in and then DataSink back out to Excel.
It ended up being quite a long winded workaround to overcome product limitations.
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