I would like to construct the Excel File Name as a concatenation of field values (and text).
One idea is to concatenate the desired filename in a hidden calculated field on the DataPage,
and then submit this field in the File name textbox on the Advanced tab of the Result Page options
https://howto.caspio.com/faq/reports-datapages/how-to-make-the-search-results-downloadable-for-my-users/
(by default I can add a date value to the file name).
NB. The search result will be a single record.