Stuck on column layout with dynamic height elements

Hey guys

I’m really struggling on this one, so I hope you can help me out.

On my page a have a column group that contains all of my elements. Inside my column group I have a menu, and a group (Group Content) that contains all other elements on my page. Now, here is my problem: I need the menu to have a height of 100 % while my Group Content should be at the top of the page all the time.
I also need the menu to be the first item in the parent column container as it should be displayed on top of all other content.

I hope you can help me out. Any assistance would be appreciated!

All the best

Benjamin