Having a right, we’re told, to commendation (7)
I believe the answer is:
acclaim
'to commendation' is the definition.
(acclaim is a kind of commendation)
'having a right' is the wordplay.
'having' becomes 'ac' (I can't explain this - if you can you should give a lot more credence to this answer).
'a right' becomes 'claim' (claim is a kind of right).
'ac'+'claim'='ACCLAIM'
'we're told' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for acclaim that I've seen before include "Welcome enthusiastically" , "Plaudits" , "Declare" , "Extol" , "Welcome with shouts of applause" .)