Greetings Sergey,
You need to create a new module wich replaces the existing view with the custom view containing the WebBrowser control. To replace the existing view with another one you need to associate the existing view interface with the new "custom" view implementation.
To open a predefined web page you need to add WebBrowser control in your custom view. See example below reflecting how to add WPF WebBrowser control to the view.
// Form the URI to navigate to
Uri uri = new Uri(some_url, UriKind.RelativeOrAbsolute);
// Create the web browser control and add it to the view
System.Windows.Controls.WebBrowser myWebBrowser = new System.Windows.Controls.WebBrowser();
this.Content = myWebBrowser;
myWebBrowser.Navigate(uri);
? To get instructions on how to modify the existing view, follow the "Customize Views and Regions " -> "Replacing an Existing View" section.
For more info consider "Using Workspace Desktop Edition API" and "How can I use a URI passed in attached data?" sections of Workspace Desktop Edition Developer's Guide.
There are Workspace Desktop Edition Extension Samples, you may want to take a look at them as well.
Happy New Year!
Best wishes )
Roman T