You can add line numbers to the NC code output
Locate the post file that you need to edit and open the one with a .EX2 extension.  (The default folder for posts is the install path, Data\IT\var\Post2)
Locate the area towards the beginning of the file that looks like this:

Comment, uncomment, and compile the areas specified in the photo above
Now post again and you will see the numbers being output.

If you want the numbers to be different than increments of 1 go back to the Post2 folder and locate your post with the .DF2 extension on it.
Open this file.  Click on the Miscellaneous tab and set the Sequencing increment.