samba - Oct 2012 - Create user account for both Samba and Linux

Hi all,

I am trying to create a samba share using a LDAP backend. I followed the 
guide here: http://wiki.samba.org/index.php/Ldapsam_Editposix
I was very pleased with the results. However, as part of the build I had 
to setup a large chunk of IDs.

   idmap domains = DEFAULT
   idmap config DEFAULT:backend = ldap
   idmap config DEFAULT:readonly = no
   idmap config DEFAULT:default = yes
   idmap config DEFAULT:ldap_base_dn = ou=idmap,dc=samba,dc=org
   idmap config DEFAULT:ldap_user_dn = cn=admin,dc=samba,dc=org
   idmap config DEFAULT:ldap_url = ldap://localhost
*   idmap config DEFAULT:range = 50000-500000*

   idmap alloc backend = ldap
   idmap alloc config:ldap_base_dn = ou=idmap,dc=samba,dc=org
   idmap alloc config:ldap_user_dn = cn=admin,dc=samba,dc=org
   idmap alloc config:ldap_url = ldap://localhost
*   idmap alloc config:range = 50000-500000*


I then used net sam provision which created and Administrator account 
and a nobody account.
Is there a way I can make users (for samba and local system) using the 
"net" utility, the way net sam provision did?

More importantly, why did I define all those ID Numbers?

Regards