The Task Scheduler can be used with the RDP-IPConfig Tool to update the IP automated with user connection. You need to download the RDP-IPConfig Tool and extract it one the Windows Server to a location where all users have access. Next you need to open the Task Scheduler.
Give the new Task a name and configure to run it with the User account. (the tool needs to run by the same user which is connecting, as the config.ini will be stored into his user-profil).
As Trigger Event you need to add "At log on" and "On connection to user session".
Under Action you need to set the path to the RDP-IPConfig-Set.exe