Hello, Robert--
I'm not sure what you mean when you say "to the 5. Request or to the 3 and 5. Request?"
If you're asking: "Can FiddlerScript look at the Session's ID property" the answer is "Yes, of course." It's the oSession.id.
If you're asking: "Can FiddlerScript count requests of a given URL and thus track how many times a given URL has been requested" the answer is "Yes, of course, it's a full script engine, and you can create a local variable in the Handlers class like
var iTimesAsked = 0;
and then inside OnBeforeRequest you can do, e.g.
if (oSession.fullUrl == "https://whatever/whatever.html") {iTimesAsked++;}
etc.
If you're asking: "Can Fiddler's AutoResponder have multiple replies for a single URL such that they can be played back "in order", the answer is "Yes." Create multiple replies for the URL, and for each of them, tick the "Match only once" checkbox.
Regards,
Eric Lawrence
Telerik