Hi,
In the settings of your menu item, under the "products options" tab, you can select between div, table and list layouts, which corresponds to listing_div, listing_table and listing_list.
There is way to add additional layouts there.
So you have two options:
- you put the code of your custom view in a view override of "listing_list" or "listing_table", supposing that you don't use these.
- you do a view override of product / listing.php and there, at the beginning, you can use such code to force the layout:
$this->params->set('layout_type', 'custom');
supposing that you have a view file listing_custom.php