Originally Posted by
Leviticus
I have read every single fare rule document I could get my paws on and I cannot see why this shouldn't work.
There are no published rules from UA on what award routings are permitted. I'm not sure what you've been reading, but odds are they aren't official docs from UA.
Search for the bits you want (e.g. NYC-JNB then JNB-NRT then NRT-SLC and then call it in. The agent will either be able to price it or they won't.
And I would not be at all surprised to learn that US-S. Africa is not valid via Asia or that US-Asia is not valid via S. Africa, essentially rendering the desired routing at the higher prices.