Dear @lousydeal
I am not sure if I would go for this solution.
I would not give many rows the position fixed. Then you always need to tell them their position, etc.
There are two ways to go in my opinion.
But all the content you want to be fixed in one row and use the stack element. Then you can just tell that row to be position fixed.
Put the content which you want to position fixed in the CUSTOM HTML section. Then you can style it however you want it to be.
Hope I could help!
Marius