Installing Apache 2 with custom options

[Nicholas Henry]

FreeBSD 5.3-RELEASE (GENERIC) #0: Fri Nov  5 04:19:18 UTC 2004

I have apache2 running which I installed from ports. All is running
well. I would like to install the proxy module. As I'm relatively new
to FreeBSD and Unix I'm not sure which is the best way to go. Is there
a way to change the config options before doing a make. How do I do
this so I add to the existing config options with out "overwriting
them". Can you do this with ports?

Any help would be much appreciated.

Cheers,
Nicholas