[Samba] hosts allow and partial subnet

[Marc Petitmermet]

dear list members

how can i restrict access to samba with the "hosts allow" configuration 
for only part of a subnet without having to list all the individual 
ip-numbers?

e.g. we have the subnet 123.123.123.1 - 123.123.123.512 and i would 
like that only the hosts with the ip numbers between 
123.123.123.237-123.123.123.319 have access. how can i do this?

all hostnames have the following schema "groupname-c##" where ## is a 
simple number. i guess that something like "hosts allow = 
groupname-c##" is not possible with samba?

regards,
marc