A crystal report could do that by looking at the first and second relavent assignments and doing the maths
What you might consider doing instead is putting a Response Level between the state of the process when it goes into the Q and the state where someone assigns it on. That way the clock measuring is done for you and you can also nag people/colour code the incident if they haven't done the workload allocation yet. Hey it could even move the incdient to the team leaders manager! The design of this would depend on your process, but I'd certainly consider this.