Relation who is a wonderful help in the office? (7)
I believe the answer is:
grandpa
'relation who' is the definition.
'grandpa' can be an answer for 'relation' (grandpa is a kind of relation). I am unsure of the rest of the definition.
'wonderful help in the office?' is the wordplay.
'wonderful' becomes 'grand' (I've seen this in another clue).
'help in the office?' becomes 'pa' (I am not sure about this - if you are sure you should believe this answer much more).
'grand'+'pa'='GRANDPA'
'is a' is the link.
Can you help me to learn more?
(Other definitions for grandpa that I've seen before include "Veteran" , "much older relative?" , "Pop" , "senior citizen" , "Older person" .)