If I understand you correctly you want many to 1 NAT for all hosts begind your DMZ.
If so here is an example config :-
( I am assuming that your dmz interface is called dmz and you internet facing interface is called outside, if not just substitute the names for the names on your ASA )
nat (dmz) 1 192.168.1.0 255.255.255.0
global (outside) 1
job done