Will Qatar merge 2 seperate bookings if booked with qatar + changeover in Doha?

[anime001]

Booking a flight for my dad to Europe.
Don't have enough points so planning to book

Economy (Berlin to Doha) - cash
Business (Doha to Melbourne) - velocity points

Can anyone comment if they've successfully merged the booking or at least checked through the luggage all the way, thereby reducing the need to clear customs; collect baggage; check back in?

Thanks in advance.

The old man is kicking 71. So want him to enjoy that 14hr leg back to Melbourne in business, if it doesn't cause any issues.

 

[DAC1]

You’ll find your answers here and here

 

[anime001]

Thanks for helping @DAC1