Rolling access to a set of ports

[hugo]

We use pfSense to build machines behind with nat'd addresses between 192.168.1.100 and 192.168.1.199.  We also use VNC to get to those machines, generally by using pfSense:59xxx port forward's to 192.168.1.xxx:5900. Unfortunately, I have to roll these port forwards by hand. The questions, then:

1.) Is there a 'better way' to do this?
2.) This wouldn't be hard to code in php, I don't think, but I don't know what it might be called…..