Question
How do you become my agent without any physical exchange taking place? You are not offering me something of your own (as is customary when this is done in person).
Answer
An agent can be appointed verbally. I am not selling or buying anything from you. I am selling on your behalf. Money will be given by the non Jew to the Rabbi to buy the Chametz. There are other methods of transactionin Jewish Law which are used as well.
All the best,
Rabbi Yirmiyahu Benyowitz