Create a Prompt window in your script
Add this command (Edit menu > Command) to your script to give you a window prompt that will fill the field of your choice with a value that you type into the prompt:
cValue=INPUTBOX("Please enter value to fill","Enter value","") *last parameter is a pre-filled value |
The command above gives you a window prompt allowing you to type in a value, and that value will fill into the field named zip.