Hi,
This will be something like policy based routing on the ASA device which is not supported.
This is not recommended but u can use the NAT statements to do this on the ASA device:-
object network obj-any
subnet 0 0
(VLAN-A,WAN1) source dynamic any interface destination static obj-any obj-any
(VLAN-B,WAN2) source dynamic any interface destination static obj-any obj-any
I think this should work.
Thanks and Regards,
Vibhor Amrodia