I'm assuming you're running on a windows NT/2000/XP machine, and that apache (or maybe just the CGI script) is running as another user than you are. you can do 2 things:

1. run apache as a user with more permissions.
2. change the permissions of the networked directory, to allow the apache user to access it.

I'd go for option 2.

How you should do this is up to you, I don't know enough about windows :-)

Joost.