Select a specific OID in the Device Template

Hi,

I am creating a new Device template for a Juniper switch. I put the right MIB in the OpManager mibs folder. Then I created a new template for the right SystemOID. Then I associated a CPU monitor to this template. The problem is that Juniper has several sub-OIDs under the CPU OID. The wizard doesn't let me choose a specific OID but only the main leaf.
Is it possible to specify the OID manually instead of choose it with the "MIB Browser"? The problem is that under the main OID I have several sub-OIDs and most of them are always 0 so the average is not correct. It would be better if I can choose a specific sub-OID.

See the attached screen-shots.

Thanks,
Roberto D.