Hello Mariangela,
This community is for Db2 LUW questions.
You might want to try the Db2 z/OS community to see if you can get faster assistance:
https://community.ibm.com/community/user/groups/community-home?communitykey=621c2a2a-01f9-4b57-992f-36ed7432e3bb
I hope that helps!