Avoid it. It's based on AR_Analysis table (old ARX file). It's summarized numerical buckets of info that gets amassed when posting invoices, cash receipts and similar. It's for the whole company code. You can't slice it / dice it by customer or by invoice date (range) or exclude by customer, division or customer type. It's just something pretty you show in an executive staff meeting along with other non-descript charts you find in the BI Dashboard to distract from the primary discussion of poor financial performance for a period. Think Sage exec meetings of the Pascal era.
Your idea to modify the A/R Aging Report is an xlnt one. Another one is dare @JeffSchwank that it's not possible to construct sheets of summarized pivot table data in Excel then create charts with it.