Are you referring to mounting a netbios share to the linux filesystem? If so, just use (taken from the smbmount help)

mount -t smbfs -o username=tridge,password=foobar //fjall/test /data/t
+est
[download]

I'm really not sure where expect.pm has anything to do with you mounting netbios shares. And I'm really not sure what the Perl part is..