Opmanager 7, delete custom monitor

How can I delete a custom created monitor.
Currently I'm trying to create a custom template for Bluecoat appliances, but when I load the mibs from Bluecoat, and I want to select the SNMP OID to query for example CPU usage, I can not manually type the sub value I want to get.

See bellow for detail:

[root@dstl01 current]# snmpwalk -v1 -c dst-ro proxy USAGE-MIB::deviceUsagePercent
USAGE-MIB::deviceUsagePercent.1 = INTEGER: 9
USAGE-MIB::deviceUsagePercent.2 = INTEGER: 80
[root@dstl01 current]# snmpwalk -v1 -c dst-ro proxy USAGE-MIB::deviceUsagePercent.1
USAGE-MIB::deviceUsagePercent.1 = INTEGER: 8

So from the usage MIB I only want index 1, but I can not select it, or type it in manually. How can I fix that?