Properly using VB's GetObject in C#

I'm rebuilding some old code we use to to do some LDAP upkeep and the one issue I've had moving it from VB to C# is understanding how to use GetObject properly.

The below example is what currently works in VB but I cannot get it to work in C#.

Dim deUser As DirectoryEntry = Result.GetDirectoryEntry
Dim ObjUser = GetObject(deUser.Path)
Dim sAccountExpires = ObjUser.AccountExpirationDate.ToString()

The issue is the AccountExpirationDate property, I can't find anything within ObjUser that looks even close to that. Any suggestions?