ASP.NET, SQL Server, WPF, C#, VB.NET

I know this is probably an easy question but I have not come across 
 
this before. 
 
We have a block of 5 static IP's.  One IP is used for our WAN 
 
connection on SBS another IP is used for our security camera system. 
 
What I would like to do is use a third public IP for a second building 
 
we're occupying and I would like to be able to access SBS through the 
 
third IP as if it we're on the LAN and not a public IP. 
 
How do I configure ISA to treat the third IP as part of the LAN? 
 
Any help would be greatly appreciated. 
 
Kevin G

Cris Hanna (SBS-MVP) wrote: 
 
Both of our buildings are plugged into the same 2Wire DSL router.  Does 
 
that change anything? 
 
Thanks, 
 
Kevin G