Question : How to  configure my net ?

Hello guys,
here is my setup :
I have an internal network with 192.168.0 network ID.
on a windows machine I have 2 NIC
1st NIC 192.168.0.1
2nd NIC 89.108.108.190 (real IP)
Subnet :255.255.255.248
Gateway : 89.108.108.189 (Real IP of my DSL Router)
DNS 89.108.129.44 (DNS of my ISP)
DNS 89.108.129.45  (DNS of my ISP)
now with this configuration, any user on my LAN can have access to the internet.
I have tested it and it is working.
my pb is that I have 2 users (CEOs) that need also to have static IP
(I have no pb since I have bought 8 IPs)
1 for the router and 1 on my MDameon server so I am left with 6
I set up the following :
2nd NIC 89.108.108.191 (real IP)
Subnet :255.255.255.248
Gateway : 89.108.108.189 (Real IP of my DSL Router)
DNS 89.108.129.44 (DNS of my ISP)
DNS 89.108.129.45  (DNS of my ISP)
and they get internet access and everything...
but they lost connectivity to my local LAN (192.168.0) and they also lost
connectivity with my MDaemon email server (that is on 192.168.0.1)
how to fix that ?
is there a way to "route" the requests to either 192.168.0.1 OR 89.108.108.189 (DSL Router )
pls help
thanks

Answer : How to  configure my net ?

Is the internet connection sharing enabled?