Foolestroupe - Thanks for the info and the warnings. In the meantime, last night, I remembered about the Sudo thing, but haven't got very far yet.
I used to know how to move files around with MSDos at the time of Windoze 3.1 as it was often quicker than trying to use the file manager. Haven't done any of that for about 10 years though!
I am currently looking on the web for info on the LINUX command line and shell and examples of how to use them (the sods keep wanting to show me how to write programmes though!). I need to sort out what the commands are for this system. Hopefully I will then be able to do what I need, either by copying a file in Superuser Mode, or by editing the text of the file in situ.
Quack!
GtD.