To my knowledge there is no way to automatically convert a spool file to excel using CL. You would need to convert the program that creates the spool file so that it creates the excel sheet instead of the spool file. I do this quite frequently and the users love it.
See this thread for instructions: https://itknowledgeexchange.techtarget.com/itanswers/how-to-export-data-from-as400-in-excel/
If this seems to be above your skill level, Google for a command called CVTPFXLS. You can then change the spool file program to write to a work file and then use the CVTPFXLS command to create a down and dirty excel sheet for the user. If you decide to go with this method, I would suggest that you get up to speed as soon as you can with the first method I mentioned as it is so much more flexible than CVTPFXLS.
After you create the sheet, you will need to find some way of delivering it to the user. You can do this either by mapping to a folder on the IFS or by having the program email the sheet to the requesting user.