mac address blocking

[parteek]

we have a window 2003 server ent. edition and through vpn
connectivity we are accessing the application of our server but the
problem is that we need a security at the entering level i.e. we
need an authentication for a particular mac address (system)


whenever the user login into my server to access application
then at server end we need a authentication i.e. permission to
allow the user.



Also we have a fortigate 60B firewall for vpn connectivity.



pls provide the solution for the above.


parteek