Link and fill cells in workbooks

[Larry]

rivate Sub Workbook_Open()
Range("A65536").End(xlUp).Offset(1, 0).Select
Selection.Value = Selection.Offset(-1, 0).Value + 1
End Sub

I have this code thanks to DS, and I have a good number generator. I would
like it to place the new number into the existing number cell so only one new
number shows up when the workbook is opened.
Better than that would be getting a solution for this:
Problem:
I need to have several workbooks that are titled by year (for autos)
in each are several tabs(sheets) the equal the unique auto number.
On each of the sheets are various discrepancies found for each auto.
So, I now have a number generator. Can I set it up so that all sheets and
Workbooks are linked in a way that when a workbook is opened and a particular
Auto selected: a new discrepancy is to be entered manually, when the operator
Clicks on the column "waiver no" (the new generated number); can it be set
to ask "new number?" yes/no, if yes it automatically goes to the new number
workbook, generates the new number and then populates the cell just clicked?

In this way the number generator workbook could just stay in the background.


thanks to all you who help us newbies out!