Primary Domain Networking

Dear All,
My question helpfull for all the IT persons and also the revision for the Experts.

1. I have a primary Domain(Head Office) in London(www.abc.com)

2. We have secondry (Branch Office) in Pak (www.abc.com.pk)

3. We want to create another branch with name of (www.abc.com)

Issue is how we can configure or what is the best proceedure and requirements to connect 2 and 3 to 1 location through VPN(Virtual Private Network).