I know that you can use Ctrl+[ to link to a cell automatically where a formula might be in use. What is the keystroke combination to go back to the original cell?

This keystroke combination doesn't normally show up on any shortcut list, so please don't suggest I go to Help and click on keyboard shortcuts. This seems to be one that is not documented or else is a customer generated shortcut. If that is the case and there is a way to create a custom shortcut to enable this process, please let me know how to do this. I am not as proficient in Excel as I would like to be, which is the reason I am asking for help.

I am using Excel 2003.

Thanks!