The OP and I worked on this one on IRC... Our main problems were these:

• $smbfilehandle isn't a "real" filehandle, it's a number that SmbClient uses to track its open files
• XBase uses the value of the 'fh' parameter like an object, so we need an IO::Handle for this
• Filesys::SmbClient doesn't provide a tied object like when using IO::Handle, so we must either use special read calls, or only builtins
• It's possible to make a subclass for XBase that knows how to work with SmbClient, but that's quite a bit of work.

I think using mounted locations is the simplest solution, but in case any monk has an idea... it would be appreciated.