Were running nw65sp7 with BM3.9.1

The servers IP is today and all workstations are on the
10.20.42. subnet.

Now we are required to connect our workstations to a DHCP (windows I think)
which is out of our control. This will place the workstations in a new

My questions are:
1. How do I change the IP on the NW server so my machines can connect to it
when they are in the new ip-range
2. Will it be a problem that the workstations are getting their IP from a
DHCP which we dont control ?