Identity Manager - C# Mapping Script Documentation

I need to port the following VB script to C# because I can't change connector scripting language anymore.

I can't find any documentation about that. Any help? Thanks

Imports VI.Projector.Connection
Dim dn AS String
dn = SystemObject.Connection.QueryObject(SystemQuery _
 .From("ADSAccount") _
 .Select("DistinguishedName") _
 .Filter(String.Format("SAMAccountName='{0}'", $VRT_Manager$))) _
 .Result.First.GetValue("DistinguishedName").AsString
return dn