Inquiry: How to set the crontab job permanently

[hadi motamedi]

Dear All
We have set a new scheduled task through crontab job list , as the
followings :
#crontab -e
30 23 * * * cp ~www/db_backup/cdr/cdrFromMSC* /tmp
It is functioning correctly but we will loose it after server reboot . Can
you please let us know how we can set it permanently even after server
reboot ?
Regards
H.Motamedi