Hi,
This would require some proper development if you wanted me to give you all the code you need to add.
I can only give some hints here.
In the view file which displays the add to wishlist button, you should find some code like this:
Code:
<a class="<?php echo $css_button . ' ' . $css_button_wishlist; ?>" rel="nofollow" href="<?php echo hikashop_completeLink($classical_url); ?>" onclick="if(window.hikashop.addToWishlist) { return window.hikashop.addToWishlist(this); }" data-addToWishlist="<?php echo $this->row->product_id; ?>" data-addTo-div="hikashop_product_form" data-addTo-class="add_in_progress"><span><?php
if(!empty($this->row->product_addtowishlist_message))
echo JText::_($this->row->product_addtowishlist_message);
else
echo JText::_('ADD_TO_WISHLIST');
?></span></a>
So that's the code you would have to change to change the javascript in the onclick with your own code and change the href with a custom add to cart URL link with the parameters as I talked about.
