Customizations

If you want to modify a prompt, you need Modifier. The only other alternative is a Customization Site License which allows someone else (usually your partner) to make the change and you to run it. It's a little cheaper.

If you want to add a field, the Extender product is one of the best options to be able to add fields to a window without custom programming. It also upgrades well but it's also licensed separately like Modifier.

Mark

Dexterity will definitely solve your issue but it requires development & will end by you creating a .cnk file which you should add to the folder where GP is installed & by running GP, you will be promped to add new code which will show your customization.

You will require documentation regarding dexterity programming which you could find in the help file of the dexterity installation.

Good Luck