Gary, take a look at your scripting documentation, entitled:
"Running Scripts Remotely".
Here's a plan. Run a script remotely on your client systems,
and have the script copy the designated file back onto your
server. (Maybe the user's "H" drive, if the users have space
allocated to them on your server).
Then, since you have control of your server, you can pick up
the (user's) file from within their space and transfer it
wherever you want.
Provided that you have permission to run scripts remotely,
and you have permission to access data stored in the users
area of your server, then this might be easier to do than
running FTP remotely.
You got questions? WE GOT ANSWERS!!! ..(but,
no guarantee the answers will be applicable to the questions)