How to edit a program outside the teach pendant?

If the programming is fairly straightforward, and the issue is tedious data entry, then scripts are probably the way to go.
Scripts can be written in Notepad, Notepad ++, or any other ascii text editor, so you have access to a fair number of text editing features - copy & paste may be your best friend here, if you’re generating points from another program.
Use an ftp program for file transfer (we use WINSCP) to copy files over. It’s great for backing up programs from the robot also.

I’m no expert on setting this up - I have a USB stick from our IT group which loads the necessary stuff onto the UR controller - I believe the program came from here:

This allows us to remotely control the robot, and I believe is also what enables the ftp connection for file transfer.