Many thanks for your help noughtsnones and Saab Dastard- it worked well and did what it was supposed to!!
I did however find an alternative way of adding the file addresses in a folder to my spreadsheet.
Firstly, open the folder and then select the files for which you want the file names list. Hold down the SHIFT key and RIGHT click on the selected files. You will see an option called "Copy as Path". Now go to Word/Notepad/Excel and click PASTE. You will get a list of the file names, including the directory path for each file. Then it was just a case of creating the hyperlinks in Excel.
Your help was greatly appreciated - thanks again.
Ed