ISA 2004 - DHCP + MAC Address

Hello All,

Have not used ISA before now (well not before this morning).

My first task that's been given to me is as follows...

Currently we have a range of IP addresses that are statically assigned to six users.
IP's: 172.16.3.96 thru ~.101
Snet: 255.255.254.0
GWay: 172.16.2.21 (n.b. - not the default Gateway)

Currently all of these users are required to input their respective IP details each time they come into the office. And when they leave, they revert back to obtain their IP address automatically.

My query .... Is it possible to configure a DHCP solution where IP/Snet/GWay/LeaseTime assignments are based on MAC address for the above range (or any range) of IP's. This would make their transition connecting to the network each morning much less of a hassle (than it currently is) and seemless.

Hope the above query is explaination enough - I'm new to all of this and "very green" behind the ears one would say.
We are using ISA 2004 V4.

Cheers,
Cameron