How to programmatically import a block to existing view?
The indicated &quot;block&quot; you point out in the UI, is internally called a &quot;display&quot;. Displays are stored inside the view object in the display property (e.g. $view-&gt;display).
If you look at the views export code you should see the pattern of exported blocks (e.g. /* Display: Block 1 */, /* Display: Block 2 */, etc.) that's rendered by the views::export() method.
For each block (i.e. display) you should see the $handler = $view-&gt;new_display(...) followed by many $handler-&gt;display... lines that add the relevant fields/filters for that display.
To programmatically import a single display you would do something like the following:
$view = views_get_view('my_existing_view');
// @TODO: Add my new display handler code
$view-&gt;save();