Workbook numbering
 

I have a monthly summary workbook. The macro will sequentially load daily
workbooks and copy values from various cells to the summary workbook. Then
the daily workbook would be closed. I would like to refer to the workbooks by
their numbers. Are they assigned numbers by Excel consistently so that, for
example, my monthly workbook would always be (1) and the daily workbooks
(only one is loaded at a time) is #2 ?