Excel wont open from guest OS

Is there a way to open an Excel document from a server on the host OS side?

Everytime it try I try to open an excel document on my mac running Office I get a messae that says the file \\server\reports.xls. Is Not in a folder shared with the host with the host and can not be opened by the host.

My mac is running VMware Fusion 3.0 and OSX 10.6.8

My Guest side is Windows XP SP3

Thanks,