Using the JMP Add In for Excel would allow you to move all of the data from your Excel spreadsheet into JMP after any change, with one click. You were not specific about where the scripts that you copy and paste are coming from, but I am pretty sure the moving of them could be accomplished by running a simple script that could be installed as a JMP Addin. If you can provide more specifics, I am sure the community will be able to help you with minimizing your efforts.
Jim