How to exactly change the registry of winCE devices with filesync rule?
There is no need to use file-sync rule. Just get the list of script command required to set all the required registry key/values and use send script to apply to targeted device(s).
Based on the online manual at https://soti.net/mc/help/v14.5/en/scriptcmds/reference/windowsmobile.html , you can use the following command to set registry value
regset registryKey [valueName] [data]
If you insist on using file-sync rule, just add one, and paste the script content in the "