Unfortunately HP will not sell you a camera battery door. If you can find another camera that is broken with a good battery door you may have a chance.
To repair/transfer the new battery door, you will have to use a small jewerly store screw driver that you can buy at the dollar store and use it to push the door hinge bar to one side of the camera.
Then, pull the door hinge out but be careful not to lose the tiny spring that is installed in between the hinges. ( Make sure that you know and understand how to put it back the same way.) You can then pull the battery door from the camera.
Do the same thing to good camera. Practice on the broken camera first. The second time it should go easier for you. When you install the new battery door, push the hinge bar in all the way to one side of the camera. Hold the door to give you the proper alignment and then use the small screw driver to pry the hindge bar from the one side to make sure that it is equally in each of the black hinge connectors.
This worked for me. I was fortunate enough to find someone who had a broken HP MZ67 digital camera that had a "good" battery door. It took me about 30 minutes to complete the job. I hope this will help you. You can email me if you need more advice. I am a computer tech.