I actually figured it out. I ended up being able to do it in-report by simply taking the Sum from the Group A footer, renaming it and putting it in an expression in a field in the detail. I really appreciate the help. Honestly, it friggin burns me up that I spent DAYS, literally days, going through all these data transformation processes to try to nail down group sum as a non-calculated variable so I could work with it. But I figured it out in the end at least. Thank you very much for the suggestion.