No Way Know How

https://www.programmableweb.com/api-university/what-are-apis-and-how-do-they-work This analogy with power sockets is the best API metaphor I've heard yet.

finally think I've figured this out, after many attempts. quite simple really. http://stackoverflow.com/questions/3881209/keep-absolute-reference-even-when-inserting-rows-in-excel-2007 formula is =INDIRECT("[reference]") the crucial part is the quotes. presumably they turn the refernce into a literal string which obviously does not change with the workbook structure.