The ip nat statements you have mentioned works on Cisco Router not on the ASA.
If you are using a Cisco ASA firewall , then you need to perform NAT and configure Access lsits to allow traffic from Outside to the DMZ. here are the NAT and ACL statements.
static (dmz,Outside) tcp 200.10.10.1 80 192.168.1.1 80
static (dmz,Outside) tcp 200.10.10.1 90 192.168.1.2 90
access-list out-in permit tcp any host 200.10.10.1 eq 80
access-list out-in permit tcp any host 200.10.10.1 eq 90
access-group out-in in interface Outside
Hope this helps.