Hello Manami
I assume in your example you mean the following:
router(config)#interface xxx
router(config-if)#ip nat inside
router(config-if)#exit
router(config#) ip nat outside source static a.a.a.a b.b.b.b
router(config)#interface yyy
router(config-if)#ip nat outside
router(config-if)#exit
router(config)#ip nat inside source static c.c.c.c d.d.d.d
I’ve never actually configured something like this, but I don’t see why it wouldn’t work. You may have some restrictions as to the IP addresses being used. I suggest you try it out in a lab environment and see what happens. Share your results with us if you can.
I hope this has been helpful!
Laz