[WPF] -Sort item inside collection in ObservableCollection

Frnds,

I am working on ObservableCollection in my WPF Project. I have the list of collection i.e 0 to 9. Each id consist of list of details of it i.e ReportClass, ReportName etc. I want to sort the ReportClass alphabetical . SO i can bind the collection to the listbox through ViewModel(MVVM).

Kindly Refer Attachment, for clarification.

For more clarification, revert me back.
eg:
0>>ReportName:DA
1>>ReportName:AB
2>>ReportName:CQ
3>>ReportName:AA
i want  
0>>ReportName:AA
1>>ReportName:AB
2>>ReportName:CQ
3>>ReportName:DA