Cisco PIX : How to allow HQ via ISP Network going thru your LAN (branch) network.

The HQ is connected to the PIX site through the ISPs network. The HQ network should be 10.22.x.x/yy. On the basis of your above PIX configuration this should be located behind the "outside" interface of the PIX.
For your HQ coming from subnet 10.22.x.x/yy to subnet 10.45.x.0/19 you would have to configure NAT0 between these networks.

Essentially the configuration would look something like this

access-list INSIDE-NAT0 remark NAT0/NONAT for Branch to HQ traffic
access-list INSIDE-NAT0 permit ip 10.45.x.0 255.255.224.0 10.22.x.x y.y.y.y

nat (inside) 0 access-list INSIDE-NAT0

This should essentially enable hosts from 10.22.x.x/yy subnet to connect directly to subnet 10.45.x.0/19 on their original IP addresses.

* If the other Branch network needs the same type of rule then you would simply add another line to the ACL/access-list we created BUT you would use the other Branch network as the source.

access-list INSIDE-NAT0 permit ip 10.36.0.0 255.255.0.0 10.22.x.x y.y.y.y

 I got this solution from Cisco Support Community