Hi,
I am not aware of the implementation in netscreen device, but from what you have describe it looks like you achieve redirection either by NAT or by using PBR.
>>PBR is supported on ASA 9.4.1 and above, you can try PBR to redirect the traffic.
>> If the device to which you are trying to redirect traffic supports WCCP then you can use WCCP redirection feature on ASA.
Hope it helps!!!!