JCL cannot do what you want - it only tells the mainframe which programs you want to run and what resources those programs require.
What you could probably do is write a Rexx program to scan your run JCL and extract the dataset names from there and write the information to a file with a comma between the 2 names and each pair of files on a new line. Then, once a day, this file can be FTPed to your PC and brought into your spreadsheet as a CSV file. After the FTP the file would have to be emptied or deleted.
The problem I have is that people can explain things quickly but I can only comprehend slowly.