I have the following setup:

Internet ---->hEX PoE (with a static Public IP) --->RB260G (with a static local IP)

I am able to connect remotely via the Internet to the hEX PoE via Winbox.
I also want to be able to connect to the RB260G from remotely via the Internet.

Any solutions/suggestions will be highly appreciated

You can:
1) (worse) Open a port on hEX and forward it to web interface of the switch.
2) (better) Run a VPN server on hEX, so that you can connect to the whole your internal network from outside in a secure way.

XVO, much appreciate you reply.
I will go with the "worse" option.
Please excuse my ignorance, could you advise how I could do that?
I cannot see the option to forward the port on the hEX router.
Port 5 on the hEX is connected to Port 1 of the switch.

Start with Wiki: https://wiki.mikrotik.com/wiki/Manual:I ... forwarding

Have a look at this article as well: https://wiki.mikrotik.com/wiki/Manual:S ... our_Router

XVO, much appreciate you reply.
I will go with the "worse" option.
Please excuse my ignorance, could you advise how I could do that?
I cannot see the option to forward the port on the hEX router.
Port 5 on the hEX is connected to Port 1 of the switch.

You need:
1) A dst-nat rule in your IP --> Firewall --> NAT that will forward requests from WAN on some port (chose it yourself) to 80 port on the local address of your switch.
2) A rule in forward chain of your IP --> Firewall --> Filter that will allow these dst-nat'ed connections (connection-state=new connection-nat-state=dstnat) - if you use default firewall rule, you probably already have one, but you need to check it.