Network Service access to a folder on a remote SBS domain

Hi All: I have an SBS2008R2 domain running a website ("Server A"). I have a web service that needs to map and read files in a folder on a second SBS2008R2 domain ("Server B").

I can reach the folder using \\Server2\folder, but the web service (running as "NETWORK SERVICE") fails when it tries to access the folder using the UNC path.

I googled a bit, but wasn't sure if its even possible for a service to access a remote location that way?

If not, any other suggestions for making this work, short of duplicating the folder using xCopy or something like that?