Concatenate means add strings together (as opposed to adding numbers together).
Therefor, in Excel (when you have done the export), you need to add a column that adds First Name, Middle Initial and Last Name. You could also do that in Notes, but you have to modify the design, so its easier in Excel.
As for "turning on" a formula in Excel, I think F9 will refresh the sheet. Go to Tools/Options and open the Calculations tab to see if you are on automatic recalc or not.
Hope this helps.
Pascal.