editing dhcpd.conf file

[Pieter Donche]

If one wants to set up a DHCP server in such a way that that a host 
with a given MAC-address will, at any time it connects, get the same
IP address, one can record that fixed relation in the 
/usr/local/etc/dhcpd.conf file.

Now, when someone already registered his laptop, and buys a new
latop to replace the old (a different MAC address), can then omshell
be used to record the change in the /usr/local/etc/dhcpd.conf file?
Does omshell edit the  /usr/local/etc/dhcpd.conf?

Or is the only way to make changes to that file, to use an plain text
editor, make the change manually and do a 
/usr/local/etc/rc.d/isc-dhcpd restart afterwards ?