Merging two office with DHCP and WIN2k servers

There are two office A and office B.

Office “A” has win 2k server where the users are sharing files. The internet connection is using “DHCP” ip addresses. All ip addresses are private. Domain name= abc

Office “B” has win 2k server as well. The internet connection is using “DHCP” ip addresses.
Domain name= yet to be configured

I need to make the office “B” the center for the file sharing (i.e move the file to office “B” where both office “A” and “B” can share the files.

Is it possible given that I do not have a static address. If not then how do I configure with a static ip address.