Microsoft product, Excel finally breaks - another is pointless for China, say (5,5)

'china say' is the definition.
(I know that People\\u0027s Republic of China is a world power)

'microsoft product excel finally breaks another is pointless' is the wordplay.
I cannot quite see how this works, but
'product' could be 'power' (I've seen this before) and 'power' is found within the answer.
'another' could be 'r' (I've seen this in other clues) and 'r' is present in the answer.
The remaining letters 'wold' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...

'for' acts as a link.

Can you help me to learn more?