Internal Webserver Routing

[Brandon Mercer]

Ok, I have quite possibly the most trivial question ever.  Didn't see 
mention of it in the archives, but I know it's been done.... in fact, 
I've done it before, but I'm having FITS making it work now.  I've got 
my PF firewall with $external and $internal.  Behind that there is a 
webserver with an address on the same network as $internal.  I redirect 
traffic through the firewall to that webserver.  Now I just need to 
create some rule to redirect web traffic from $internal stations that 
try and hit the $external IP address to go to the internal web address 
as well.  It's SO easy... but I'm stuck.  Thanks for all your help.  Not 
really comfortable pasting my ruleset on here... but I can if needed. 
Brandon