Manage to get note supporting policeman (4)
I believe the answer is:
cope
'manage' is the definition.
('cope' can be a synonym of 'manage')
'note supporting policeman' is the wordplay.
'note' becomes 'e' (musical note).
'supporting' means one lot of letters go next to another (in a down clue, some letters go below others).
'policeman' becomes 'cop' (I've seen this before).
'e' after 'cop' is 'COPE'.
'to get' is the link.
(Other definitions for cope that I've seen before include "Join" , "Deal effectively (with a difficulty)" , "Manage effectively" , "top on wall" , "Manage to deal with the vestment" .)