Ahh, I see, I wasn't clear in what I wrote.
By non-auto-discovery I did not mean manually adding devices, but more, manually maintaining the list of measured points within the device.
An example: a device has 3 codecs, each codec has a counter telling how many video corrections it has made. You can not ask the device which codecs it has, but once you know, you can snmpget the correction counter for that particular codec.
I know which codecs each device has, it's in the "magic excel sheet". I can calculate the correct snmp OID. (or have python do it)