Rerouting remote users to VPN channel

[Ivan Gustin <ivan.gustin@pu.t-com.hr>]

Hi,

I have one specific routing situation that I still can't handle, so I am 
asking for some help.

I have Linux server, one eth interface and 2 DSL links. One DSL is VPN 
link to another site's Web Intranet application. VPN link itself is 
realised via DSL line and CISCO router. Local users can work with that 
application. Another DSL is Internet gateway for local users, and 
incomming channel for accessing server from outside (there is Siemens 
DSL router).

I want to provide that external remote users can connect to that server 
from Internet and use that Intranet application via another DSL and VPN 
channel.

Route table:
# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use 
Iface
192.168.30.9     192.168.93.65    255.255.255.255 UGH   0      0 
0 eth0
192.168.93.64    0.0.0.0         255.255.255.192 U     0      0        0 
eth0
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         192.168.93.122   0.0.0.0         UG    0      0        0 
eth0

...93.64/26 is LAN,
...93.65 is VPN gateway to Intranet Web server on another site,
...93.122 is Internet gateway,
...30.9 is Intranet Web server with The Application on remote site.

Local users can go to Internet and on Intranet app on remote site, and 
that works fine. I need rules that Internet users comming from public IP 
using http://mysite.dyndns.biz:myport through ...93.122 can go to 
http://192.168.30.9:80. I succesfully set forwarding on DSL router so 
incomming packets comes to server on port 'myport' (I can't 
reroute/rewrite packets on DSL router itself).

I tried with one PREROUTING rule, but I can't rewrite both source and 
destination address, so obviusly I need two rules?

Thank anyone for any help,
GI