I am not sure how your question relates to ReadyAPI, however ReadyAPI provides a data sink, which can write to an Excel file very easilly.
See https://support.smartbear.com/readyapi/docs/functional/steps/data-sink.html for more detail.
oh... that is too bad. We have lots of groovy code that does just what you ask. Too bad you don't use ReadyAPI/SoapUI for your testing or your problem would be solved by now. 🙂
/Alex [Community Hero]
[Community Heroes] are not employed by SmartBear Software but
are just volunteers who have some experience with the tools by SmartBear Software
and a desire to help others. Posts made by [Community Heroes]
may differ from the official policies of SmartBear Software and should be treated
as the own private opinion of their authors and under no circumstances as an
official answer from SmartBear Software.
The [Community Hero] signature is used with permission by SmartBear Software.