Adding arbitrary terms to the Search Box logic

Could someone give me some clue how to add new 'invisible' keywords to the Search Box logic ?

I would like for example to show a product in the result list when a concurrent product's brand name is entered in the search box.
I cannot add the brand name in the product name for obvious (trademark rights) reasons, although I think it would be totally legal to offer our visitors a similar product when a partical brand name is being searched for.  (kind of adwords-like logic in the inner search)

Custom code...
You could use JavaScript on the client page (View/.cshtml file) - but note that it becomes fodder for SEO
Or, you could put code in the appropriate Controller