VM flatlist 3th level in new column on hover

Dear Developers,

I am using joomla 2.5
Template Beez5
Virtuemart 2.0.20b
I am also using the params module.

Problem,
In the attachement you can see my maximenu on an active state fixed on the menu "webshop". This is a virtuemart flatlist menu.

I would like to happen that the 3th level (sub)menu for the parent "webshop" menu shows up in a different collumn that only shows if I hover over the 2nd level menu.
menu's with big blue letters in screenshot. 3th level menu's are shown in smaller black letters.

I am trying for some time now and cant find anything about it on the internet and your forum.

Any help would be appreciated.

Thanks in advance!

Hi
Please check this video to see how to arrange the columns in an ecommerce submenu

CEd