SMS Notification (on-call scheme)

We use an on-call rotation scheme. Where each week another engineers mobile phone will receive the notifications. Since this is not a feature in the current version of OpManager, we hacked ourselveves a solution by altering the the contents of the database. This seems to work for escalations but not for notifications. If I go to notifications and save it, it'll work. Could you either tell us, how to solve this and/or implement an on-call scheme in the notifiation and escalation function.

This is how we alter the database:
UPDATE smsprofile SET TOADDRESS="<email-sms-gateway>" WHERE PROFILEID=1501;
UPDATE policyuserprops SET PROPVAL="<email-sms-gateway>" WHERE NAME="EscalationPolicy_Backup" AND PROPNAME="toAddress";

Kind regards,
Jilles Groenendijk