I can remember making his work, but if I remember correctly, I had to direct the call to an extension set up to remote forward to the external number. You can select this as a destination from an auto attendant as it will treat it as an extension. I don't think a networking access code is a valid entry in Class 25.02, unless you're routing to networked system, in which case you have to point the call at a far end extension.
Sometimes the thoughts in my head get so bored, they go for a stroll through my mouth. This is rarely a good thing.