Hi Craig_s,

I can make the "pin0001" part but other than manually typing in the
".jpg" (and the list needs to be 1016 numbers long!!) I can not work
out how to append the extension.

Use an extra column and this formula:(assuming filenames without
extension start in cell A2)

=A2& ".jpg"

Regards,

Jan Karel Pieterse
Excel MVP
http://www.jkp-ads.com