Stand out — Microsoft program (5)
I believe the answer is:
excel
This clue is a double definition.
'stand out' is the first definition.
(I know that stand out can be written as excel)
'microsoft program' is the second definition.
(Microsoft Excel)
(Other definitions for excel that I've seen before include "Perform exceptionally well" , "Perform extremely well" , "Show brilliance" , "well above average" , "Succeed, stand out" .)