I don't believe standard LDAP/Active Directory has anything like this.
Computers are just another class of AD objects - but there's no "link"
between a user and one (or multiple) computer(s) - there's no
belongsTo attribute on the
computer class, nor is
computers collection on
If your organization has implemented an extension to the default AD
schema (which is entirely possible!), it's a custom solution, and then
you must know what it is! :-)