"What are you actually trying to do - simple resave a spreadsheet under another name? Or are these spreadsheets outputs from a program and you're trying to redirect the outputs to another format? Or what? " - I'm not sure where you got that from, but as you say you don't understand spreadsheets.
I thought "I have a workbook "PPrune.xls" which has 3 worksheets, 1, 2 and 3. I wish to be able to select which of the three (or all) I save to a new workbook 'Danny.xls", 1,2 and 3. I'm happy with the selection, and can save the first sheet as sheet 1 - it is adding the next 1 or 2 I am stumped on."
was pretty straightforward to anyone who understands Excel/Libre-Office programming, and I suspect it is. Hopefully someone will come along one day.