newbie IPFW user

[Da Rock]

I'm relatively new to IPFW, not FBSD; the last time I used IPFW (I 
believe) was using 4.3. I'm now attempting to use IPFW for some tests 
(and hopefully move to production), and I'm trying to determine how I 
would setup binat using IPFW; or even if its possible at all.

I've been hunting some more in depth documentation, but it appears to be 
scarce/not definitive. I suspect using the modes in libalias such as 
"use same ports" and "reverse" might be able to do what I'm looking for?

Any clarity much appreciated.