You cannot edit that VI, but you can get it to recognize your own error codes.
Go to Tools>>Advanced>>Edit Error Codes and use the dialog there to create your own error file (note that the numbers should preferably be different from other error numbers).
Be sure to save it in the default location and give it a -errors.txt postfix.
Then, restart LV and the general error handler should recognize your errors as well.
When you build an application, you should also have the option of including your errors file in the build.
___________________
Try to take over the world!