AngularJs + maintain infinite scroll position on postback

We use AngularJs in one of our project. We have a div which contains static header which is strict all the time. Below that there content div which contains <ul> and list of 10 <li> so when this page loads, header is there which is fixed and all <li> is scrollable when we scroll down and reach end of div, more <li> loads dynamically and this continuous as user keeps scroll down. Now consider user click on any one of <li> is opens up detail page for that element <li> On detail page there is back button, takes user to list page but on this page, it refreshes and shows data from start and not where user scroll down and found related product he/she gone to detail page. So we need to maintain position e.g if user has scroll 5 times and loaded dynamic content 5 times means in user's view, items are showing like 51 - 60 so postback, user should see same view and not from begining. Important note is : Header is fixed and just content is scroll able. So in your reply, let me know what you understand. and provide fixed cost. Your deliverable will be a zip containing this implementation.