Active Directory - DirectorySearcher & DirectoryEntry

I was thinking something like this:

oGroup.Invoke("Add",newobject[] { oUser.Path.ToString() });

//oGroup refers to a group from domainA and oUser refers a user from domain B.

//oGroup is the directory entry from a active directory search for a group from domainA.

//oUser is the directory entry from a active directory search for a user from domainB.

Thanks in advance.

Best Regards,

Rodrigo Guerreiro