[TYPO3-shop] Default product per category

[H.E.Weenink | Aristo WebDesign]

Dear people. 
 
In tt_products it can be done to assign a default category and a default
productitem. So far so good. But how about this one: 
 
We have more pages with each a category, 
when the page is choosen it opens a list in 1 category AND and it should
open a default product in this category. 
When another page (with other category) it open list AND should open a
default producti in that second category.
 
How can this be done?  
 
Regards, Eef