I need a commercial lawyer to draft a non enduring power of attorney with limited use (Victoria)

I am a start up looking to receive bills on behalf of clients from utility providers. I would like to draft a Power of Attorney that is very limited in allowing me to change the email address of the client to one I specify or if the customer receives paper bills receive electronic bills to the same email address. As per origin this is the information that I will require in the cover letter.

In this letter the attorney will be a company

-All Origin account numbers including Including LPG / Solar HP accounts if known
-name the Origin account/s is held in
-legal authority's full name, date of birth and contact details