Well , good news is that I found the solution and it is an easy one.
I added netbios aliases to the smb.conf file and mapped same drive letter with to a different aliased servername for each user.
Now that all users connect from the same client to the same file with different pid numbers on Samba / Centos server ...
More details can be found in the attached file. ( I can not upload here, receiving errors ! )
Here is the original link : http://h20000.www2.hp.com/bc/docs/suppo ... 037826.pdf
Credit goes to Eric Roseme from HP.
Thanks a lot for this paper