Global fields can be used if the file is shared and your scripted finds will work just fine. The thing that differs with global fields and a hosted file is that a client of the database cannot make lasting changes to the value of a global field just be editing it and changes made to a global field by one user are not visible to other users.
For a scripted find, this is exactly what you want as it keeps one user's search from interfering with another when they enter their criteria into a global field.
The "You can't use global fields" entry is misleading. You can't enter find mode and enter search criteria into a global field whether the file is shared or not. But as these scripts demonstrate, you CAN enter find criteria into global fields while in Browse mode, then have the script enter find mode and use the criteria in the global fields to produce the needed find requests for your search of your database.
Thanks for clarification. Exactly what I needed to know.