I'm not familiar with the .LIS file format, and a quick search on the
web says it's a VAX programmer file- which doesn't sound like your
situation. When you say "report readable file" do you mean it is meant
to be printed on a line printer, something like a .PRN file?

Sometimes you can trick the software by renaming a file extension. If
you'd like to try this, make a backup of your .LIS file, rename the
backup file to .TXT, and try to open that with Excel or Notepad. If it
works, Excel will prompt you to parse the data into columns and go
through its usual file import dance.