Clients need Different IP at each Logon

We have several mobile staff using notebooks to logon to our network. At the moment they have to manually change their IP address and gateway, reboot to access different subnets in the network. ie: different branch locations. Is there any way that the user can be prompted to enter the IP for there location, or choose from a predefined list at startup?
note: These clients access the network over different different routed subnets.