pix ip address outside = 1.1.1.1
pix ip address dmz = 192.168.200.1
webserver = 192.168.200.10
webserver outside ip = 1.1.1.2
static (dmz,outside) 1.1.1.2 192.168.200.10 netmask 255.255.255.255
access-list outside permit tcp any host 1.1.1.2 eq 80
access-group outside in interface outside
or if you're using 1.1.1.1 to access webserver you could have this...
static (dmz,outside) interface 192.168.200.10 netmask 255.255.255.255
or port translate like this...
static (dmz,outside) tcp interface 80 192.168.200.10 80 netmask 255.255.255.255