Automatically create iPad logins from existing computer logins

We have been using PCs and are now adding iPads to our list of devices. All staff have an existing login for the PCs. As far as we can tell, we can only manually create the logins for the iPads. I want to create them automatically, e.g. from a spreadsheet with existing usernames and passwords. One additional hurdle is that the iPads require one additional character for the passwords - we want to add an 'x' to the end of each existing password. I don't want a freelancer to create the logins; I want a tool or resource to take the list of existing usernames and passwords and create the login for the iPads.