Extract data from bkper
here is not a specific extracting tool for bkper, but there are several ways for you to extract your data and use it elsewhere.
CSV - Export data to a CSV file with the content according to any query you want.
Google Spreadsheet - Use the bkper add-on to extract data from a book to Google Sheets. On the add-on select the right book, query and combination of data to extract, press fetch and bkper data will be written from the active cell on.