Hello,

I have a few tables containing different exam data for students - and a unique identifier with each. I need to add another unique identifier (which is already specified from another system).

Now, can I use the existing identifier (UPN) to automatically put in the new identifier into a new field (AdNo).

If that makes any sense at all, I will be surprised...thank you!

As long as your second table has some thing to match to the first table (I am guessing UPN) then yes, you can use an update query to do it. In the query designer specify the table the table to update, join the second table to to it. Drag the new column to update to the middle row. In update to specify the table.NewID to place in the new column.
basically