Custom Monitor aving multiple sub-OID

Hi,

I have a Juniper switch EX4200. I created a template but I found that the Juniper CPU and Memory OIDs are not leaf but they have sub-OIDs one for each chassis instance: fan, power supply, Routing Engine, Forwarding Engine and so on. Obviously the CPU is applicable only for the RE or FE not for a fan or a powr supply! This is the same for the memory. (Juniper makes a good job isn't it? :-( )
Unfortunately OpManager takes in account the average of those values that it is always very low or even zero because many of the sub-OIDs shows 0.
At the same time I cannot pick only one specific OID (with the Add Bulk feature) because there are at least 3 or 4 of them that needs to be taken in account.

My question is: is it possible to change OpManager to take in account the maximum value (peak) and not the average? That will be simpler.

Thanks,
Roberto D.

Here some extra info:

http://www.juniper.net/techpubs/en_US/junos10.0/information-products/topic-collections/nog-baseline/cpu-utilization-monitoring-using-mib-summary.html

user-nms % snmpwalk -Os -M /volume/~/mibs -m all tp1 public jnxOperatingCPU

jnxOperatingCPU.1.1.1.0 = Gauge32: 0
jnxOperatingCPU.1.1.2.0 = Gauge32: 0
jnxOperatingCPU.1.1.3.0 = Gauge32: 0
jnxOperatingCPU.2.1.0.0 = Gauge32: 0
jnxOperatingCPU.4.1.1.0 = Gauge32: 0
jnxOperatingCPU.4.1.2.0 = Gauge32: 0
jnxOperatingCPU.4.1.3.0 = Gauge32: 0
jnxOperatingCPU.4.1.4.0 = Gauge32: 0
jnxOperatingCPU.6.1.1.0 = Gauge32: 224
jnxOperatingCPU.6.1.2.0 = Gauge32: 224
jnxOperatingCPU.7.1.0.0 = Gauge32: 2
jnxOperatingCPU.7.2.0.0 = Gauge32: 2
jnxOperatingCPU.8.1.1.0 = Gauge32: 0
jnxOperatingCPU.8.2.3.0 = Gauge32: 0
jnxOperatingCPU.8.2.4.0 = Gauge32: 0
jnxOperatingCPU.9.1.0.0 = Gauge32: 6
jnxOperatingCPU.9.1.1.0 = Gauge32: 0

user-nms % snmpwalk -Os -M /volume/~/mibs -m all tp1 public jnxOperatingDesc

jnxOperatingDescr.1.1.1.0 = midplane
jnxOperatingDescr.1.1.2.0 = midplane
jnxOperatingDescr.1.1.3.0 = midplane
jnxOperatingDescr.2.1.0.0 = Power Supply A
jnxOperatingDescr.4.1.1.0 = Left Tray front fan

jnxOperatingDescr.4.1.2.0 = Left Tray second fan
jnxOperatingDescr.4.1.3.0 = Left Tray third fan
jnxOperatingDescr.4.1.4.0 = Left Tray fourth fan
jnxOperatingDescr.6.1.1.0 = CFEB Internet Processor IIv1
jnxOperatingDescr.6.1.2.0 = CFEB Internet Processor IIv1
jnxOperatingDescr.7.1.0.0 = FPC @ 0/*/*
jnxOperatingDescr.7.2.0.0 = FPC @ 1/*/*
jnxOperatingDescr.8.1.1.0 = PIC: 4x OC-3 SONET, MM @ 0/0/*
jnxOperatingDescr.8.2.3.0 = PIC: 1x Tunnel @ 1/2/*
jnxOperatingDescr.8.2.4.0 = PIC: 1x G/E, 1000 BASE-SX @ 1/3/*

jnxOperatingDescr.9.1.0.0 = Routing Engine
jnxOperatingDescr.9.1.1.0 = Routing Engine PCMCIA Card