Active Directory automation : copy users from a group to another and modify attributes

I didn't know Powershell and someone asked me to copy users from a group to another. We are talking of about 300 users.......Impossible to do it manually.
They asked also to modify (I remember this was the wrong day for me), for those users, the "Dial-in tab" in Active Directory (for Radius authentication).
After some search I found dsmod, dsget and an interesting VBScript that I've adapted to my environment.
This is what I've done :

Exchange 2003 & mailbox queries.....no powershell

We needed to query AD from Exchange 2003. We know that this version is not fully "queriable" by powershell.
I'd to understand how to retrieve some important information. We had for example an archiving system that use the group membership to "understand" if your mailbox is "storable" or not.
I took the opportunity also to grab other useful info .....let's see
Why don't use AD query tool ?

So let's do some queries to understand the structure.