• to use a rule in /ip firewall mangle to assign a routing-mark (which is in fact a name of a routing table)
• to use rules in /ip route rule for the same purpose.

There are two ways to achieve what you want:

• to use a rule in /ip firewall mangle to assign a routing-mark (which is in fact a name of a routing table)
• to use rules in /ip route rule for the same purpose.

Using a mangle rule, you can assign the routing mark based on in-interface or src-address or src-address-list and even some other properties of the packets; ip route rules match only on source and destination addresses or subnets but don't interfere with fasttracking which may be a significant advantage if the Mikrotik's CPU is weak.

The common part is
/ip route add dst-address=0.0.0.0/0 gateway=pptp-out1 routing-mark=via-pptp-client

The individual part is
/ip route rule
add action=lookup-only-in-table table=via-pptp-client src-address=the.ip.assigned.to.the.pc
or
/ip firewall mangle
add action=mark-routing new-routing-mark=via-pptp-client chain=prerouting src-address=the.ip.assigned.to.the.pc
/ip route add dst-address=0.0.0.0/0 type=blackhole routing-mark=via-pptp-client distance=2

The additional route is necessary to prevent packets from the PC to use the default routing table (called main) if pptp-out1 is down. With /ip route rule, it is not necessary because action=lookup-only-in-table prevents packets from being routed using the table main (i.e. the one consisting of routes without any routing-mark).

If you need the address of the laptop assigned by the VPN to be accessible as a server to other hosts in the UAE's network as clients, the solution will be a bit more complex.

And one remark regarding terminology, a "local address" is one of device's own ones. The address of your laptop assigned by Mikrotik acting as PPTP server is "an address from a connected subnet" from the perspective of the Mikrotik, not a "local" one. It seems unimportant till the moment you start using a match address-type=local in firewall rules and it does something else than what you expected.

Please briefly describe one of the methods with command.

Please briefly describe one of the methods with command.

That's what I already did.

The common part (i.e. the one you have to use regardless which method you choose) is to create a specific routing table consisting of a single (default) route, and the command was given there:
/ip route add dst-address=0.0.0.0/0 gateway=pptp-out1 routing-mark=via-pptp-client

What to do next depends on method chosen, that's why I've given it in the form

list-of-commands-for-method-1
or
list-of-commands-for-method-2

What other commands do you ask for?