But I don’t see how to add something that’s in a different portion of the tree like:

I had to do something very similar to this recently. The approach I took was to simply abstract each of the OID's I needed to query into a hash, like so:

my %oids = (
    sysdescr        => ".1.3.6.1.2.1.1.1.0",
    model           => ".1.3.6.1.2.1.47.1.1.1.1.13.1",
    flash           => ".1.3.6.1.2.1.16.19.6.0",
);
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In your case, you could do something like:

my %snmpstrings = (
    "Interface Description" => "interfaces.ifTable.ifEntry.ifDescr",
    "System Uptime" => "system.sysUpTime",
    # etc...
);
[download]

I'm sure you get the idea :)

--Darren