Users on my network have static IPs.
Do I have to modify the templates under the directory /etc/e-smith/etc/smb.conf for achieving this?
No the original template (which should not be modified) should be located at /etc/e-smith/
templates/etc/smb.conf/. Locate the proper fragment and copy it to the same directory layout in the /etc/e-smith/
templates-custom/ tree, create the necessary structure using mkdir if it does not exist. Modify the copied fragment in the templates-custom tree, this way you will not loose your changes made on upgrades of the e-smith-samba packages.
For more information on the template system see the SME Server Developers Guide linked from the wiki.