Simply create new dummy Gateway object without defining its topology using one of the loopback IPs, for instance:
![image.png image.png](https://community.checkpoint.com/t5/image/serverpage/image-id/1157iB6C3E87B31F624F9/image-size/large?v=v2&px=999)
Change your "Install On" in NAT Properties of the objects slated for Static NAT to the dummy gateway:
![image.png image.png](/t5/image/serverpage/image-id/1158i04A0E542E68C569A/image-size/large?v=v2&px=999)
Define policy installation target as "Specific" and point it to the gateway it is originally designed for:
![image.png image.png](/t5/image/serverpage/image-id/1159iEF022A62E2CB278A/image-size/large?v=v2&px=999)
Publish changes and install the policy.
Subsequent NATs from these hosts will be subjected to the NAT applied on the Network object, if any:
![image.png image.png](/t5/image/serverpage/image-id/1160iAB202447470AB6AB/image-size/large?v=v2&px=999)
Of course, you can script the object's NAT target change to do this in bulk, once the dummy gateway object is created.