this loop through your “parent_folder_path” including subfolders for excel files, and copy each one to your “destination_folder_path”

for /f "tokens=*" %a in ('where /R "parent_folder_path" *.xlsx') do copy "%%a" "destination_folter_path"

A simple recursive loop over *.xlsx files and copy them is sufficient here:

for /r "P:arent Folder" %%a in (*.xlsx) do copy "%%a" "D:estination Folder"

Adapt the file mask *.xlsx to your needs (maybe *.xls*, or (several masks are possible) *.xlsm *.xlt*

There are reasons to use ? for /f with ('where... or ('dir..., but none of them applies here.