I assume by 'relocate computer accounts' that you're trying to change the dn (distinguished name) of the entry in LDAP (ie, move the accounts within the LDAP tree). You can either use Mozilla::LDAP or Net::LDAP to issue a modifydn command, provided your directory supports it. You can also use one of them to generate walk the tree, and generate an LDIF that you can then apply using ldapmodify. (which is probably what I'd do, just because I'm paranoid, and would want to keep a record of exactly what I changed)

If you're just trying to modify which machines people are able to log into, you probably just need to set something in their record. (PAM uses 'Host', but I have no idea what Active Directory uses to tell what machines a user has access to). I also have no idea if there's anything that would need to be done at the host level, as I don't do windows administration. (in Unix, you'd want to create their home directory, if it isn't on a mount point that's shared between systems, and so would already exist)