Hi Manuel,
probably the best way to do it is to make a separate (window) procedure, with a NetWebClient object.
this can be fully automated to send the request to the other server, and get the reply, and then feed that reply back to the calling procedure.
You can use one of the WEbClient examples to develop this procedure, experiment with the right settings for it and so on. Then copy the procedure across to your web app.
The window itself can be set to "hidden" in the web app, so it never appears on the server.
cheers
Bruce