Having AI create the spreadsheet you want is totally possible, just like generating bash scripts works well. But to get good results, there needs to be some documentation describing all the hidden relationships and nasty workarounds first.

Don't try to make LLMs generate results or numbers, that's bound to fail in any case. But they're okay to generate a starting point for automations (like Excel sheets with lots of formulas and macros), given they get access to the same context we have in our heads.