How to update a value in a .txt using in a post request ?

Hello everybody, i’m trying to write a test which create new user on our ASP.NET app. The app use some old security mechanism like state variable (__VIEWSTATE and __EVENTVALIDATION). The gatling recorder create a file named CreatePratician_0006_request.txt. But in order to be able to replay the scenario, i have to replace some values extracted from the incoming request in that file. Sadly, i have no idea how to accomplish such a task ?


The file with the request parameters is in attachment. 


PS: Does someone have any good tips or resources on how to use gatling with ASP.NET app ?

CreatePratician_0006_response.txt (55.9 KB)