No. You can only redeem for excess baggage using either Qmiles or Qcredits * per redemption transaction. In case you do not have sufficient Qmiles or Qcredits, you can select the cash option to proceed with your redemption.
For more on excess baggage awards, click here
*Redemption of Qcredits for excess baggage is applicable only for Platinum and Gold members. Read more about Qcredits.