As far as I know, the only way to have the list of accounts is to use FMPro Advance and create the "Database Design Report" (it is under the menu "Tools")
Another option is to set up an "account management" system of tables, layouts and scripts such that accounts are created by entering the needed data into fields and then a script sets up the account. Then the same script can log the account name in a table and you can list the records from that table to see the current list of all accounts.
This, BTW, makes it possible to set up a user to manage accounts even if they themselves do not have a full access account--if that's a useful option for your system.
thanks, I had come to that conclusion too. It works really well.