Thank you Ana for your suggestion, I will try it.
However I've seen that on the server there are already some schedules that are using a .xaction file.
I've downloaded this file that is a zip file that includes three files: a file .xaction, a file .xaction.local and a file called exportManifest.xml.
In these files there are some references to the job.
I've duplicated and renamed this file, changed the references to the job, created the new zip file and imported it.
Now it seems that the new chedule works,
I don't know if the production of this .xaction file can be automated.