How to add windows domain users to a local group ?

[el dio]

Hi, i'm trying to add domain user to a local Windows group.

Imagine I have domain 'myDomain', domain user 'myDomain\domainUser', my computer is 'myComputer', local group is 'Guests'.

I used many approaches but neither worked. The latest code I have used is following:

DirectoryEntry domainUser = new DirectoryEntry("LDAP://myDomain/CN=domainUser,CN=Users,DC=myDomain,DC=local");
DirectoryEntry computer = new DirectoryEntry("WinNT://myComputer,computer");
DirectoryEntry guests = computer.Children.Find("Guests", "group");
if (guests != null)guests.Invoke("Add",new object[] { domainUser.Path.ToString() });

This code throws exception with message "Invalid path"..

Any ideas how to do it ?