Navigate to specific tab within ViewPagerIndicator

My setup is as follows: I have tabs setup with a ViewPagerIndicator in my Main Activity. In TAB3 I have a ListView where the items within it launch a new Activity containing a WebView. In that WebView I have a link, which when tapped I'd like for it to close this Activity containing the WebView and navigate back to TAB1 in the Main Activity.

I'm fairly certain I'll need this piece of code [http://docs.xamarin.com/recipes/android/controls/webview/call_c#_from_javascript] to get the link in the WebView working. But I'm stumped about how to close the Activity and navigate to a specific tab within a ViewPagerIndicator.