The title says it all. How can I do this ?

Caveat: my ISP only allows ports above 1024.
Is it enough to add an iptables rule, redirecting e.G; port 2323 to the router's internal IP port 23 ?

eg:

Code:
iptables -t nat -A PREROUTING -d \$2 -p tcp --dport 2323 -j DNAT --to-destination 100.100.100.1:23
All tips welcome,

BigOoze