On the drink heading to North Country (5)
I believe the answer is:
niger
'country' is the definition.
(African country)
'on the drink heading to north' is the wordplay.
'on' becomes 're' (regarding).
'the drink heading' becomes 'gin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to north' says the letters should be written backwards (in a down clue, letters go up or 'northward').
're'+'gin'='regin'
'regin' reversed gives 'NIGER'.
Can you help me to learn more?
(Other definitions for niger that I've seen before include "W. African country" , "22 across (anag) -- northwest African river" , "West African republic" , "Country in interior of N Africa, capital Niarney" , "Land-locked country and river of W Africa" .)