Robsony,
You're welcome, and I'd be glad to elaborate on the solution.
Portal alias background:
When you type in www.yourdomain.com -- DNS is set up to direct that to your DotNetNuke site. Now, DotNetNuke can have many portals, each with their own domain name if you wish. Therefore the portal alias table is a way for a single DotNetNuke site to service many portals. So in essence, when your web site receives a request, it looks in the portal alias for a matching URL and then takes you to the appropriate portal. If it does not find an appropriate URL it will take you to what it finds (and in your case this is your local address 192.168.1.1/webshop).
Solution:
You need to add your Portal Alias to the portalalias table in the database. You can either A) go through the host -> portals section of the web site on your development machine and add a new portal alias for your production site and then backup/restore your database to your production server. Or -- you can manually enter the portal alias in the your database table (portalalias) on your production site. If you choose the latter, remember that you need to restart your application for this change to take effect. You can restart the app by making an arbitrary change to the web.config file.
For reference: The option B) SQL statement that you would need to run in your database would look something like this:
update portalalias(httpalias, portalid)
values('www.mydomain.com/website', 0)
Also, if you need more information or clarification on any of this -- a simple "updating portal alias" search on google will yield several helpful results.
hope that helps!
Take care,
Ian