I read the OP as saying there are 3 computers involved. An XP file server, the users laptop, and a Solaris box. The current state is that a user must access the XP box with their laptop to FTP the file to the Solaris box. I belive the OP wants the Solaris box to pull the CSV file from the XP box via SMB. (I would assume the XP box does not have a FTP service running.)
My only experiance using Samba is either sharing files from Linux or using smbmount (or mount with an appropriate -t setting) to access windows files. smbmount //host/share /mount/point has worked for me, but it prompts for username and password if needed. There should be command line options to set those if needed.