Hi,
There is not really a solution for that, a workaround could be to fill the custom field value with "{loadmodule X}" where X is the id of the desired module. (this is a Joomla feature).
So before setting the custom field, you will have to create as many modules as category ID you want.
Then thanks a simple view edition, for example the view "product / show_default" display the content of your custom field thanks code like:
echo JHTML::_('content.prepare',$this->element->CUSTOMFIELD_NAME);
www.hikashop.com/support/documentation/1...ize-the-display.html