How to change cookie value after login to aras instance

Aras stores the cookie value to  "ASP.NET_SessionId" which remains the same on login/refreshing page/ opening in another tab or window, I tried updating cookie value using simple javascript function through innovator.aspx it gets updated but login page doesn't appears and when i tried to update using login.aspx it creates new cookie with same name but different value. I tried "System Events"(on successfullLogin) from TOC too but nothing worked...have anybody tried this before...we have requirement from client that cookie value should get changed on login for some security reason

here is snippet of my code:

//Javascript function by generating some random string

function setCookie() {
  var randomString= (Math.random()*1e32).toString(36)
  document.cookie = "ASP.NET_SessionId="+randomString+";max-age=3600";
}

//Aras server event

CCO.Context.Session["SESSION_COOKIE_DEFAULT"] = "someValue"