Yes. It is possible, but he will have to speak to someone in Legal Assistance. If he is in a location where he does not have access to a Legal Assistance office, he needs to talk to the Judge Advocate assigned to service his unit. If there is not SJA locally, the unit should have a Command Judge Advocate (CJA) assigned. Finally, there may be a paralegal (MOS 27D) assigned to the unit who can also help him with this. Any of these people can assist the soldier in preparation of a Military Power of Attorney; however, I would confirm with the bank that is releasing the funds (the bank that needs the POA) that this will be acceptable for the bank's purpose. While there is no reason that the Military POA should not be accepted, some banks have their own format for a POA, and may only accept that format. In any event, if you can get the soldier a copy of the bank's POA, any of the above individuals should be able to help the soldier complete the POA, and have it notarized.
Based on your location, I am assuming that the soldier is based out of Lewis-McChord, so if the soldier is having problems with this, you may be able to go and get the local Legal Assistance office to provide guidance on where the deployed soldier needs to go to get Legal Assistance.