I’m not sure what “10.0.0.10 = 1.1.1.1” means, maybe NAT 1:1 mapping? If so, add 10.0.0.10/16 and others to WAN and use 10.0.0.2 as default gateway. Then anything sent to 1.1.1.1 should come to your 10.0.0.10, etc. And similar with srcnat, your outgoing 10.0.0.10 should get srcnatted to 1.1.1.1 on ISP’s router.
Doesnt make sense.
The more important facts which you have not provided is
A. What did you ask for?? or perhaps be in reality
B. Is this a homework question??