One problem might be the format of your delimiter string, I think you are using double quotes enclosing single quotes in your first expression used in the SET vNonUsageSummaryRevenue1. Try removing the double quotes, a string using single quotes around the comma should be enough.
I assume your CODE is a number or literals, but not a date or a dual or something thats need special formatting.
If so, you don't need to use quotes for the list of values in your set expression element set.
Looking at your second approach, I also think that formatting the vUsgInv in a way enclosing the CODEs with quotes is causing the problem here. At least while trying to reproduce your issue, this is what I've seen using QV11.