simple nat setup

Here is what i am trying to do really simple I hope. I have a second IP address from my ISP that I wish to assign to a device behind my mikrotik router. So say my second ISP address is 172.20.5.10 and my lan device is 192.168.1.8. The mikrotik sits on 172.20.5.8. How can I tell the mikrotik router to forward Ip 172.20.5.10 to 192.168.1.8

Thanks

if you have assign the 172.20.5.10 to same interface of your first ip, you could try this command

/ip firewall nat add chain=dstnat dst-address=172.20.5.10 action=dst-nat to-addresses=192.168.1.8

Thanks worked great