Filename extensions are not unique (have a look at
http://www.filesuffix.com/).
In a soaring context, let's suppose that '.cup' is used with SeeYou,
and '.dat' files are to be uploaded to some Cambridge hardware.
In this case, both are actually '.txt' files with a specific suffix.
Change '.cup' and '.dat' to '.txt', and open them with Notepad (or
Wordpad, ou Word...).
This will show you how data are to be arranged and formatted.
Once you have the example, it is a simple matter to open the original
'.cup' file in Excel, (Open as 'Text file' [¨.prn;*txt;*csv]),
re-arrange data, concatenate them as required,
save the result as a '.txt' file and rename it to '.dat'.

Willy VINKEN

On Tue, 21 May 2013 22:17:15 -0700 (PDT), nimbus
wrote:

Trying to find a link to a site that will convert my .cup waypoint file to a .dat file. I've tried the GPS babel site ( http://www.gpsvisualizer.com/gpsbabel/ ) with no luck unless I'm just selecting the wrong extension options.
Thanks for any help.