Query Netbios Domain Name. Please support me on. As Brian Desmond points out this is not necessarily the authoritative way to find the actual netbios name it is merely coincidence that they usually correlate.
The NetBIOS name cache is checked for the NetBIOS nameIP address mapping of the destination host. The leftmost DC will contain your netbios domain name. This would show you the computer name.
Or just get the users domain name.
In the original release version of Windows 2000 the upgrade routine clears the check box that links the primary DNS suffix of the domain controller to its DNS domain name. This would show you the computer name. This order can be changed by configuring the NetBIOS node type of the client. When a user initiates a NetBIOS name query by using an application or service such as net use the NetBIOS name resolution process begins.