Class design for an app that reads data from Active Directory

I am hoping someone can help me regarding design and architecture for an application. The application is basically a service written in C#. The purpose of this service is mainly to read data from Active Directory and Save it to a local database (that data is later going to be used for reporting purpose but that's not in the scope of this application). The attributes for an Active Directory object and my database fields doesn't always have one to one mapping. So for example, let's say I read 3 attributes of a User AD object and based on those 3 attributes I set a flag in database column (so here in this case it's 3-1 mapping between AD attribute and database field). I am also going to collect the extended attributes from Active Directory (those attributes I am going to read from an XML file and I will pass it to Active Directory API query). There could also be custom AD objects (not necessary AD object like User, Contacts, Groups etc. But they can be a completely new custom object that is not present in AD by default OR could be an extended object like a special user extending from standard User AD object). For reading AD attributes I am using System.DirectoryServices API of .Net.

Initially I was exploring Domain Driven Design to implement this application but since I don't have much business logic and there could be a lot of unknown entities (custom AD objects), I was just wondering what is the best way to design such an application? What will you guys suggest?

I will be really very thankful for your help.

Tklee