I'm not sure if I'm using this correctly. In this little bit:

if eval spellarray[index] == ar_BadNumericIndex
;do stuff
endif

I know for a fact 'index' in not a valid key, but the 'do stuff' never triggers. Am I using this right?

Anyone?

That's likely the problem. If the script can't process the 'index' part, it won't be able to progress to the 'do stuff' part.

Use testexpr instead of eval. ar_BadNumericIndex is used to compare array keys, not elements.