The Floating Panel does not allow classifying the applications in any alphabetical order.

However, what you can do is make a backup copy of the file ‘AppControl.ini’ located here:

C: \ program files (x86 \ rdplus \ userdesktop \ files \ AppControl.ini

Open AppControl.ini with a Notepad and edit it: change the order of the applications from [App6].

The applications assigned in the Floating panel will then have the desired display order.