Hi,
There are two parameters:
1. In the joomla options of your hikashop content module, you have the module suffix class option where you can put _menu so that the module uses your template's menu module style.
2. In the hikashop options of your hikashop content module, if you're displaying the listing as a "list", you can set the UL class name option to the same as your menus. That depends on your template so we can't guess the name without seeing the website with both a normal menu module and your hikashop module.