[Samba] SAMBA authentication

[Augusto Casagrande]

Hi I´m new here.
Here is my question : We have severals servers running on our net. We have
one Win NT4.0 (domain manager), one SUSE Linux 8.1 running Samba 2.28.
We need to validate user/pass from Win NT4.0 from , for example , an
external application ( made in Java ) .
Is there some command we can call , given an user and passwd ? ( for
instance : "validate user , pass, in_server" )
My english is not too good , I can explain more if anything is missing.
Regards!

Augusto