Hello Ben,
The script we referenced will work correctly only if the CSV file contains user sAMAccountName property. If you need to update users from a CSV that does not contain the property you will need to use another script.
Also the script will not work if the column headers contain properties Display Names (e.g. First Name), they should contain properties LDAP names (e.g. givenName).
If you need a script that will work around these requirements, could you provide us with all the information about the CSV file you will use for updating users?
For more information about importing user accounts from CSV files, check the following tutorial: http://www.adaxes.com/tutorials_ActiveD ... SVFile.htm.