Repeater and port forwarding

[gt_gr]

Hello, I work for a company that often needs to control customers' computers and we are interested in using the SCIII method.

However, we need the 443 port to be used for a website that's being hosted on our server, and so we can't have this port open for the ssl repeater.
Instead, we have installed the ssl repeater on a local machine and forwarded a different port (like 8765) to that machine's 443 port.

If I try to connect to a machine using the internal network ("local-ip:443" set in helpdesk.txt) everything works really well. The same can't be said for when we try to connect to an external computer.
In the latter case, the address in helpdesk.txt uses our public IP address and the port we're forwarding to the repeater (like 12.34.56.78:8765). In this case, connection fails with this message:

Connection failed - Invalid protocol !

Possible causes:

- You've forgotten to select a DSMPlugin and the Server uses a DSMPlugin
- Viewer and Server are not compatible (they use different RFB protocols)

The only thing that's different is the IP used to connect from the SC (local IP vs external IP), the port (443 VS 8765) and the ID used for the connection.

I'll draw a couple of diagrams to make it clearer.

The following works all right:

PC1 <--has the SC
|
Port 443
|
v
PC2 <--has the repeater
|
Port 5900
|
v
PC3 <--has the viewer

The following does not work:

ExternalPC <--Has the SC
|
Port 8765
|
v
Company router
|
Port 443
|
v
PC2 <--has the repeater
|
Port 5900
|
v
PC3 <--has the viewer

Is there any way to use SCIII without having to forward public 443 to the repeater?