guide for using sorttitle instead of title

[raylapse]

While using fuse2 skin, I would like to view posters in the order of sort title but not the title(lable), and I expect the a-z filtering can also work with sort title. Simply changing the jsonrpc call will make the global search work with sort title, but the a-z filtering system is much more complicated.
Would you kindly give me some hits? It seems the a-z filtering system is deeply integrated with script.variables.