Deal with more general cell specifications

[jennybc]

E.g. (excel) Sheet1!$C$2 or (google sheet formulas) R[-2]C[-4]

https://support.office.com/en-ie/article/Create-an-external-reference-link-to-a-cell-range-in-another-workbook-c98d1803-dd75-4668-ac6a-d7cca2a9b95f

https://support.office.com/en-IE/article/define-and-use-names-in-formulas-4d0f13ac-53b7-422e-afd2-abd7ff379c64

https://support.office.com/en-IE/article/guidelines-and-examples-of-array-formulas-feeac856-88a1-4219-95a5-40107a1b4365

[jennybc]

Another wrinkle. In Google Sheets, the R[x]C[y] style of specification appears to be absolute when combined with a worksheet-specification (example: Sheet1!R[x]C[y] but relative to the host cell otherwise. I need to absolutely confirm this but that's my current hypothesis.

In Excel, I believe square brackets always imply relative reference.

[jennybc]

https://support.office.com/en-us/article/Overview-of-formulas-d258ec72-149a-42ac-8eae-b50a667eb491#bmusing_references_in_formulas