Robin, a hyperlink from the topic area of the course was made to the text file that has been upload into the course. Pop up windows don't seem to make a difference to the £ not displaying. I can change the 'Encoding' sub-menu, but suspect not all students will go down that route.
I think the best solution is to copy and paste the information into the 'compose a text page' resource which works and probably should have been used in the first place!.
Many thanks