Thanks for the help. Even with that option, it looks like that is only for subscribing, not publishing?
Here's what I found to be the problem.
When I write a user script in the Windows program notepad++, then copy it to the modem using WinSCP, the mosquitto_pub command within the script does not work.
However, when I open the file off of the modem directly in WinSCP, edit it using the WinSCP editor, then save it using WinSCP, the script works great. I think there is something about the way it is saved in notepad++ that the modem doesn't like. I don't know why. Thanks for the help.